I'm more excited for this game than Diablo 3. Primarily because this game won't be using Bnet 2.0. 
what's bad about bnet 2.0
Forced region locking (a huge one for me. I have some friends who live in the UK and I can't play Starcraft 2 with them unless I buy the PAL version or they buy the NTSC version)
No LAN (irrelevant in my case, but missing features aren't cool)
No chat rooms
Real ID (I know it is optional, but I hate the concept. I don't want to know my e friends IRL and I sure as hell don't want my RL friends to know I play Diablo 3)
All mods have to be uploaded to Bnet and become the property of Blizzard. I think this is a bad idea because it is going to discourage people from trying modding. I downloaded a Diablo 2 mod yesterday that essentially turned it into Diablo 2.5 by overhauling all the skill trees, adding new quests and enemies.
Bnet 2.0 can, and probably will, change between now and Diablo 3's release, but it is currently underwhelming (at least from what I played of SC2).