Since there's been all this talk about poetry readings on the blogosphere lately (or at least in the derelict corner of it that I haunt), I figured I'd weigh in on the subject with my two cents, if only because it's Sunday and it's too cold outside to go out (yes, Percy, if Winter comes, Spring can be very, very far behind).
As I see it, readings as they've evolved today, generally have two distinct parts. The reading itself, and the Q&A that follows. Let's start with the Q&A. In my (admittedly limited) experience, Q&As following readings are generally snooze-fests, with questions ranging from the trivial to the inane. And I think there are good reasons for that. Nice as it would be to believe in some Athenian ideal of spontaneous public conversations giving rise to blinding insights, this is extremely unlikely to actually happen. Meaningful discussion requires a level of honesty, that the norms of politeness attendant upon a public conversation make difficult; respect for the opinions of others, which is hard to muster in a room full of unscreened strangers; shared assumptions, understanding and language, that a group of people randomly gathered are unlikely to have; a clarity of agenda that these meetings almost never have; and a quantity of time and patience that is incompatible with the format of a 15-20 minute Q&A. It's hardly surprising then, that most public Q&A's end up being exchanges of trivial platitudes. It's the same reason why having an intelligent debate on the Internet is nearly impossible.
Could moderators or discussants help raise the level of conversation? Perhaps. But aside from the practical difficulty of finding intelligent discussants, there are at least four problems with the discussant model. First, it's not clear what exactly the discussant's role is. If the discussant is expected to ask questions that are of interest to the listening audience, then a good discussant will, logically, ask more or less the same inane questions that the audience would have asked itself. After all, that's what the people really want to hear. Even if the discussant were capable of initiating a genuinely meaningful dialog with the poet, in doing so he or she risks alienating the audience, who may neither understand nor care for what is being discussed. Second, is the exchange between the poet and the discussant / moderator a conversation or an interview? If the former, then we need to ensure that the discussant is someone capable of contributing to that conversation, which suggests that he or she should be part of the reading as well; if the latter, then what, exactly, is the poet supposed to be getting out of this? Third, in either case, why is this exchange taking place at the end of the reading in front of an audience. Why not do it either in private, where both people could talk more freely, or record the conversation and broadcast it either through print or other media?
Finally, why do we believe that a verbal conversation is the best way to engage with a poet anyway? Poets aren't stand-up comics or politicians. Providing coherent, even glib answers at the drop of a hat is hardly their strong suit. If anything, what we value about a poet is often his or her ability to take an idea or an image and after long hours of contemplation, find the exactly right way to put in words. To then turn around and expect the same person to fluently respond to questions on the fly, and to judge him or her on his or her ability to do this seems irrational, if not outright cruel.
All of this suggests that Q&As as they are currently run are largely a waste of everyone's time, and makes the case for either scrapping them entirely, or, at the very least, making them an optional extra - much like discussions with the cast and crew are at film screenings or dance performances. It also suggest revisiting the format of the Q&A, perhaps switching it to a discussion or panel between multiple poets reading at the same time, though even that (and even assuming the best case) will not fix all the problems listed above.
So much for Q&A. Let's consider the reading itself next. And in doing that, let's start by accepting that as a medium of delivery the spoken word has several disadvantages over its written counterpart. First, reading a poem means that all spatial arrangement of words on the page is necessarily lost (unless the poet uses Power Point - which I've never seen or heard of a poet doing), and such arrangements (and the caesura that attend them) are an integral part of the poet's craft. Second, poetry, with its compactness, is an art of hidden meanings, of verbal and mental booby traps. There may be people who can follow a poem in a straight line from start to finish, but when I read a poem I usually end up going back and forth over the text, ferreting about among the words to catch the scent of the meaning, and that's hard (or at least harder) to do when you're hearing the poem read aloud . Hearing a poem read aloud, then, may cause us to miss out on its subtler aspects.
Finally, there's the problem of interpretation. Great poems work by leaving themselves open to various readings, multiple interpretations. Hearing the poem read aloud, especially if the one reading it is the poet, can end up imposing one official interpretation over all the others. It's not unlike the feeling you get when you watch the movie version of a book you love - how either the disconnect between the images on the screen and the images in your head is so severe that you cannot take the film seriously, or you accept the onscreen depiction and are then never able to think of the characters and images in the book in any other way.
Overall then, the spoken word as a medium for poetry has several disadvantages, and all of the above is assuming at least a base level of competence in the reader. Add the possibility that the person reciting the poem may actually damage or obscure its meaning and flow and the downside is even greater.
There are, however, compensations. A truly good reading can bring a poem alive; can enrich our understanding of it, enhance our experience. What this requires, however, is something more than a vanilla reading. It requires, in the truest sense of the term, a performance. And that in turn requires both talent and preparation on the part of the one performing. The problem, of course, is that many (if not most) poets neither have the requisite talent nor are willing to put in the effort of preparation.
And why should they? If the poet's primary role is to write poems, then this requires neither a talent for public performance (reading and writing are inherently private acts - it's what draws many of us to them) nor a desire to take on the onerous distraction of prepping for such performances. This is not to suggest, of course, that poets should go unprepared for readings, or that they should not do readings at all. It is to suggest that if we start to think of reading poetry as a specialized performance, independent of the main business of writing poetry, rather than as a natural and normatively necessary extension of the fact of being 'a poet', then those poets who also happen to have the talent or desire to be performers can put in the time and effort to put together readings, while others (I suspect, but cannot prove, the majority) who have no such talent or ambition can not bother with readings all together .
Switching to a view of readings as performances in themselves has two further implications. First, it would mean that we could hold poetry readings to a higher standard - essentially the same standard that we hold other forms of performing art to - and this would mean that we're more likely to get exciting, adventurous readings rather than the familiar spectacle of a poet droning on from behind a lectern. And this in turn may actually increase attendance at readings; I know I'd be more willing to attend readings (which I currently tend to avoid) if I thought that poet's decision to do a reading was the signal of a deliberate and considered choice, rather than just a knee-jerk reaction to something he or she was expected to do. And greater attendance in turn would motivate those looking to perform poetry readings, thus setting up a virtuous cycle, from which everyone - audiences, poets who want to perform their work, poets who don't want to perform their work (or suck at it, and are introspective enough to know this) - would benefit.
Separating the writing of poetry from its performance also brings us to the question: why do poets read their own work? Playwrights almost never act in their plays (at least not outside of high school dram socs), scriptwriters rarely appear in their movies, composers may occasionally conduct or play the piano in their pieces, but I've never heard of a composer singing his or her own arias, and certainly there's no expectation that the composer will be the exclusive or primary performer of his or her work. Why do we insist that poets, arguably the least capable of all artists at performing in public, retain their amateur status and read their own poems? If we want to hear poetry read aloud, why not subscribe to division of labor and get professional actors / performers to do the reading? The petty vanity of poets aside , it's hard to see how handing poetry readings over to the professionals could do anything but improve the experience for all concerned.
Finally, once you get rid of the Q&A, and focus on the performance aspect of the reading, you're left with the question of why, in the Internet age, we persist with brick and mortar readings. There is, after all, no dearth of sites that host readings of poems, both by poets themselves and by other performers, and posting a reading on the Web means the poem is likely to reach a wider audience, and that audiences are likely to get more reliable quality. What, then, makes attending a reading a superior experience to listening to poems read on the web, and reading the text itself on the page or screen? We go to live music events because the concert experience is far more exhilarating than listening to the song or piece at home. We go to movies because staring up at the big screen has an effect that no TV or monitor can duplicate. What is it about the average reading that is so much more thrilling than hearing the poem read online? And, more to the point, if we want poetry readings to continue, what can we deliver in a physical reading that we can't over the Internet?
 It's interesting that readings of ghazals / other poems in Urdu (or at least depictions of them in the media - I've never actually attended one) usually involve repeating each line several times, just so the audience can fully take in its meaning
 The other argument that's made for readings that it helps poets reach out to an audience. I'm skeptical about this, if only because I don't know who these people are who won't read poems in books / journals, but will show up at a poetry reading of someone they wouldn't otherwise read, or why, as a poet, I would take them seriously. In any case, the idea that readings are a way for people to discover new poets and for new poets to be discovered, only makes the point about public performance not being the poet's primary expertise more salient. We need to resist the celebriti-zation of poetry - a world where the first screen by which a poet is judged is how well he or she performs in public is a world where poetry is considerably diminished.
 Personally, I think a lot of this reading mania is driven by the fact that there are more people out there who care about being poets than about writing poetry, which makes readings the perfect format. But that's just my (probably biased) opinion.