I don't know, I don't think of Wilson as dark. He just makes me want to take care of him. But that might be my blazing Robert Sean Leonard crush that goes back to Dead Poet's Society (ahem, I'm aging myself). Anyway, here's what RSL told TV Guide:
Any chance we'll see a Wilson-Cuddy hookup on House? — Allison
MICKEY: I suppose this is a natural progression after we all lived through Huddy, but Robert Sean Leonard disabused us of that notion when we asked. "I think [Wilson] is a dark guy. He has three ex-wives, he lives alone, deals with death every day and his best friend is House," he says. "So when I think about him with Cuddy, it doesn't work." Fine, so then maybe there's someone else out there for him? Not for now, says Leonard. He'll just have to content himself with a domestic partner (as in roommate) in House. They'll be going apartment-hunting together soon.