I'm not waiting on no starcraft expansion! To me personally, 90% of gameplay value of this game is in multiplayer. I beat the campaign once, I liked it, especially the jukebox soundtracks ("Zerg, shotgun" anyone???) But I don't see myself replaying it anytime soon. So, the only real benefit is the new units that may or may not be in it.
I agree with the first post that they finally need to get D3 out the door. One could be tempted to throw SC people on Diablo project instead. However, as we all know “adding more workers to a project running behind schedule will make it even later”. Blizzard never set a release date for D3, so it cannot be late by definition, but I feel this rule would still apply. So, D3 is just going to come out whenever it comes out…