Ultra? A year. High? Maybe three.
I don't think IB will do much. Kepler and the rest of the 7000 series will probably be a bigger deal. Remember, though, that you can always wait for the next big thing. I think the 7970 would be a good idea; it's the new generation and its performance is impressive. The 2500K is a marvel, and with a good OC it'll handle two 7970s (your next upgrade) without trouble.