I haven't ordered my badge yet (need to do that soon) but the hotel is booked! We're staying at the penthouse of the Embassy Suites!
I didn't go last year after having gone to the previous four and I missed it a lot (even though I made up for it by visiting a bunch of ENW friends along the east coast including Piratecat). So I'm really excited about getting back this year.
My one bit of advice is to pack your schedule with as much stuff as humanly possible. Play five or six games a day. Eat unhealthy food in the 15 minutes between games. Drink a lot. Sleep very little. Rest up the week AFTER GenCon.

*sticks tongue out at BrentNall*
Seriously though, the way I tackle GenCon is not for everybody. I've discovered that every year I go I spend less and less time in the dealer hall and more time hanging out with the friends I only get to see once in a while. I think I spent about 45 minutes total in the dealer hall last year.
Official Games: Never played one. I only play and run games with ENW/CM folks and I wouldn't have it any other way. The quality of these games is just astounding and there is no better way, in my opinion, to learn to become a great GM while having the time of your life than gaming with these people. I highly recommend it.
Also, make time to drop in and hang out at some of the parties thrown at the Embassy (I have a pretty strong feeling that the one on Wednesday night will be in the penthouse). You might even get to meet BrentNall (and his wife is SMOKIN' hawt).
Dammit, now I'm all ready for GenCon! Why'd you have to start this thread?!