Never Played WoW, but Starcrap 2 was awful IMO.... It was so tired and used.. it's formula felt archaic, and once I saw that people fought in giant "deathballs" i was out. The Dawn of War series has twice the innovation and creativeness that Starcraft 2 has... even though I didn't like the direction of the 2nd DoW game. Didn't even get Diablo 3 but I've heard it's awful. It's like Blizzard's entire reputation is based off stuff they did nearly a decade ago.
I mean, I find it hilarious that they basically carbon copied the Warhammer universe 10 years ago... and now they're so far gone that they've added kung-fu pandas to it... haha