Nothing official yet but it seem the
Las Vegas Convention Center's calendar is
listing it in their schedule that BlizzCon 2010 will take place in Sin City July 30 and 31. Now you do have to schedule this things a long time in advance and I know Blizzard was worried about trying to hold the amount of people that were trying to get in.
Next year would be a pretty solid year with
StarCraft II probably being released and more polish on games such as
Diablo III. Of course, we'll get more
World of Warcraft content but could Blizzard announce something big that they really need a big venue to hold all those that want to get in?
Blizzard has not confirmed or denied that that's the location of the next BlizzCon and it is a ways away but if Vegas is indeed the place, I might have to it the convention for the first time.