Very disappointed at HotS.
Storyline, well, it's crap. like Zaphid says pretty much nothing moves the plot forward, It's like WoL never happened, she's still the same. I expected some "bonus missions" ala Zeratul in WoL where I could play some "protoss" campaigns with the new units, wasn't there.
The S in RTS wasn't really there, build zerglings and ultralisks and attack with OP Kerrigan, faceroll GG.
Yes, cinematics are great and I think Blizzard has always shown that they have some great artists and CG modelers, but the game itself is crap, DEFINITELY NOT WORTH 60$. In a sense, it reminds me of Quake 3, its main focus was multiplayer and they developed a "single player campaign" just to have something.