Look, if you don't care much about the Starcraft universe, or if you weren't really attached to Brood War as a childhood experience and a milestone in dark, complex, betrayal-and-intrigue game storytelling (somewhat), you could probably have fun with the Starcraft 2 single player campaign. It has fun mission designs, the last mission was pretty fun, and the ending won't drive you to SON I AM DISAPPOINT levels of contempt like it did me.\\
The thing that really gets me is the poor quality of the Hyperion-side animation.
I couldn't take infested Hanson seriously, for example, she was just incredibly poorly animated. So was Raynor in armor. It destroyed the scene. And every time I have to look at Matt's face I keep wondering why there's a low-rez Kaiden Alenko on my ship.
Huh, those actually didn't bother me that much. I was generally, though not universally impressed by the animation.
Though I was annoyed by the horrible...wait I don't know if you've gotten this far, but the scene at the Mobius rendezvous, which made a) no sense and b) seriously, Marine combat armor sucks THAT much?
Also, not a spoiler for you I think:
Thank **** you saw Infested Hanson. Guess what happens on the other path? She cures the Zerg virus. Yeah, she miraculously cures it when all the might of the Protoss couldn't and didn't. **** that.