I think I'm going to hold out at least unti SI. There's really no dx11 title that I'm drooling for right now. I was falling into the mental folly of being prepared for such a title when it hits...but as said here, by that time, there will be better cards for the money.
I've tossed around the idea of a complete platform upgrade...but I'm basically in the same boat in that department, as I am with the GPU. There's nothing that's all that much better than what I have for gaming/general purpose use, for the money I'd have to spend.
I'm resisting even getting a different board, keeping the existing setup, and adding another 4870 1GB...as that could be money spent on a complete platform upgrade down the road.
Used 4870x2 might be an option I guess...It feels like things are starting to stagnate a bit as far as tech goes.