AMD beat NVIDIA to the punch with the stellar 5000-series, with the Fermi taking the literal, hot seat in the competition and requiring a refresh to keep up technologically. Rumors have been flying that their 28nm-based Kepler GPU would see a launch this year (even if it were a paper launch) but it seems that is now out of the question. Ken Brown, a spokesman for NVIDIA has come out and said:

Although we will have early silicon this year, Kepler-based products are actually scheduled to go into production in 2012. We wanted to clarify this so people wouldn't expect product to be available this year.

Keep in mind that AMD are still hammering away at their Southern Islands, HD 7000-series of GPU and should make a launch before years end. Just in time for Battlefield 3. However, if you want to stay on Team Green, you'll have to wait that little bit longer.