Wombat is right. PAX is for the general public of gamers. Not for media-only showcases.
Also, CheapyD's comment of "showing a game before it's ready can really sour your opinion of it" hit home with me. I got a chance to play Bionic Commando on the 360 before it was released, and I was just so put off by the alpha build they showed me that it made me completely shun the game. My friends tell me the game isn't all that bad, but I'm still put off by it cause my first impression of it was that it was really awful.
Don't drink and drive. You might spill the beer.