Twenty contestants will be selected to have their questions answered, and if you're one of the winners, not only will your question be answered, but you'll also get a prize package containing various Blizzard swag items plus a new ATI graphics card.
The actual submission form is right here if you're interested (with the laundry list of rules here if you want to make sure you're eligible to win), and you can ask any question related to Starcraft, Diablo, Warcraft, or World of Warcraft. Good luck!
Just popping in with a quick note here; even if you're not going to Blizzard, you can still enter a contest to have a question answered live by the developers.
I braved the red tape for you all to figure out the following:
You have until 4:00 pm PST October 11th (this Saturday) to enter the contest.
You have to be at least 13 years old.
You can't be a resident of North Dakota, Connecticut, Vermont, or Maryland in the U.S., Quebec in Canada, or Queensland, Victoria, or the Australian Capital Territory in Australia. Otherwise, if you're a player in the U.S., Canada, most nations of the E.U., South Korea, Singapore, or Australia, you should be eligible. No word on Russian, Mexican, or Latin American players so you guys may, like me, be ineligible.