It's supposedly a mix between games like Doom, WoW, and Diablo, so I'm thinking that it'll probably have a deceptively barebones story that's elaborated on using quests. That's only speculation, of course, so we'll see.
So long as it doesn't have any stupid, stupid, stupid copy protection I'll probably get it for PC when it comes out. Then again, 2k is publishing it, and they're known to be complete fucking retards when it comes to DRM.