The US will always have to be ahead of the other nations involved in controlling the skies. Russia and China will be producing 5th gen. fighters within the next 10 years (Russia's T-50 I believe, can not remember China's). So we need to start thinking about the 6th generation.
The F-22 Raptor started its design phase in the 1980s, so a 6th gen won't be expected until the 2030's at least. Of course the Raptor program has been shut down in favor of the cheaper F-35 Lightning II, which just so happens to have the same airframe cost of the F-22 (currently $200 million USD per plane)
Of course the Lightning II is much more of a multi-role aircraft than the near strictly air superiority F-22
For the 6th Gen. fighter they are moving towards a more unmanned approach, but are trying to achieve the balance between the thinking capacity of a human, and the flight capabilities of a UCAV.