I wrote up this article to help people get started for the #BlizzChat tonight.
http://felfire.com/warlock/twitter-developer-chat/
I wanted to rally up as many voices as I could to get involved and asking the hard questions.
If you have any good questions that you plan on asking Blizzard for the #BlizzChat, leave them here or at my site in the comments so I can add them to the post. (I am constantly updating it)