In terms of strike aircraft, the air force is placing a big bet on the T-50 fifth generation strike fighter. Sixty of these planes are expected to be procured starting in 2016 (originally planned for 2014). While four T-50 prototypes are already being tested by the air force, by all indications new engines and advanced electronic systems (and especially its avionics) are not yet ready. This may lead to another round of delays in serial production.
Swiped from Russian Military Reform.
As the US has found the 5th generation fighter technologies area bit tougher to develop than those that came before. Given our experience with the F-22 and now F-35s, no one ought to be surprised that the PAK-FA/T-50 has slipped in its development & procurement schedule. As the author notes, there is likely to be another procurement slip as well. It may be that the entire project may slip as much as a decade: 2024 procurements rather than 2014. That's not a dig at the Russians. They are coming from behind (as are the Chinese) as far as experience in developing these associated $tech and its tough. If anything the US ought to be embarrassed by its uber slippages, especially with the F-35.