Starcraft 2 Beta doesn’t seem to be on the radar yet. As of WWI 2008 in Paris, a third of the single-player had been done. Crispy Gamer got a four=pages interview with Bob Colayco and Frank Pearce discussing several topics about Starcraft 2 including voice chat. Blizzard is looking closely at some Steam features.
Crispy Gamer: What about plans for an open beta for StarCraft II?
Pearce: A beta is very important from the perspective of getting feedback from the community and continuing that process of iteration. A beta is something that we’re very likely going to need to host. But we haven’t made any determination whether we’re going to have to host a closed beta or an open beta, or both yet.