First things first: what is the AWP conference? The AWP conference (or just "AWP" as many people call it, making no distinction between the organization itself and the actual conference) is a four day meeting put on once a year by the Association of Writing Programs. It usually happens in the first five months of the year (the academic spring semester), and each year it changes what city it's located in -- although someone on the planning committee seems to have a love of Chicago in the bitter cold of February because they return there with some frequency.
The Association of Writing Programs, technically the Association of Writers & Writing Programs, is a 40+ year old organization that grew up out of the attachment of creative writing to the academy in America.
The value of the conference is that it draws in such a large chunk of the community. Where else can you hear a dozen amazing writers read in the same place within three days time? And you'll know that you only heard a dozen because you couldn't be in two places at once listening to even more great writers read.
For me it's that the conversation about writing and teaching and publishing is taken out of the small academic group that I am a part of during the rest of the year, and opened up to the community at large. I found that every day I'd attend one panel that was a complete dud of a discussion; it didn't address anything that I was interested in. This number appears to stay constant no matter how many panels you attend in a day. Attend one and there will be one dud. Attend five and there will be one dud. If you get to enough interesting discussions you'll find something that really gets you thinking -- and you'll leave AWP with the best thing you possibly can: ideas.
The "old" image of the conference is that it's where poets get drunk and sleep around. The cynics still uphold this view. Then again the cynics seem to go only to one or two panels, say that they hate the panels, attend a couple of readings and then hang out the rest of the time in the bar. Maybe I was looking in the wrong place, but everywhere I looked the energy was decidedly more focused on the literary than the sexual. There were still quite a few people doing their best to uphold the image of writers as alcoholics, but as a whole the atmosphere fairly buzzed with purpose: like the airport terminal meets the industrious hive of bees.