I know there are a few people here who WoW so a little tidbit for you.
Blizzard is apparently accepting "opt-ins" for the Lich King open beta. Not sure exactly when it is, but that's a pretty good sign of progress (does anybody recall the delta between beta and release for Burning Crusade? I think it was still a few months).
You just go to your account settings and you can enter there.
In fact, they aren't even on the same floor of the building they all work in.
It doesn't matter because Blizzard never releases games one after another in quick succession. As a matter of fact there are at least 4 different teams working on 4 separate projects at Blizzard according to Rob Pardo. One project/game needs to be well out and stable before the other one goes to the public. SC2 might be very close to beta but it's not going to get the go ahead until the WoW expansion is out and fully supported, and in the meantime they'll most likely iterate through the SC2 builds for balancing/content changes.