I just sauntered over to the Convention Center here in Anaheim to see what I could see, and the results are in the first exclusive gallery of pictures from BlizzCon, available right there below!
There's nothing really groundbreaking here, unfortunately-- it looks like they're still setting up the banners (so I'll go over and check again later today), and I couldn't get close enough to get a really good look inside the Exhibit Hall. But they're definitely close to being done-- while there's lots of carts and equipment around, not much is coming in or going out. I did see a pallet of boxes, but I couldn't get close enough to read what it said on them. Here's an original size version of that one if you guys want to try to decipher what might be in there.
Unfortunately, no "Wrath of the Lich King" banners yet, but I'll keep my eyes open and bring you more when I find it.
Update: Added some more banners, because when I stopped by this afternoon, they were done putting them up.