Hey guitarguru,
As mgap said, it's a "Music Merchant's" convention. You must be a dealer/retailer or otherwise connected in "the biz." "Regular" folks get in (as I have) by virtue of a buddy in the biz who gets you in ...but it is a pre-registration thing...all before the event official like. But I must add that even though regular folks get in, this is a sellers' convention and their intent is to sell/deal/incite interest to retailers for quantity sales. So while a booth here and there
may cater to an individual, that's not at all their goal, and some merchants frown a bit on the individual guy walking up asking Qs ...they know non-merchants are there, but some reps are less-than-thrilled by it. Afterall, you're taking up their time and potential business connection so it makes sense that they want to devote their energy toward real retailers. If you end up going by virtue of someone else, simply be sensitive to their desires to devote time/energy to merchants.
On that note, these shows are a blast. Bring a camera, be a nice guy and smile a lot, and absorb the organized mahem. BTW, in the few I have been to, Taylor's room has been the largest and nicest by a large margin, IMHO. And I am a big Fender/Gibby guy, and the Taylor room was nothing short of phenominal. Not to mention they roll out some great performers! Just sayin
Edward