Strategypage has a brief piece on the F-15SE--Silent Eagle, noting it has some stealth features that allows it to compete with the F-35.
It isn't as comprehensive as a longer post of theirs I quoted back in April 2009, which makes it clear that the stealth features apply to a front view and only from the air. So it would not be useful as a strike aircraft into a high threat environment the way the F-22 or F-35 can be. But it would have an edge in long range air-to-air combat over an unstealthy opponent, providing a useful supplement to the stealth aircraft.
We've already decided that the F-22 is too expensive to buy many of them. It is probably safe to assume that the price of the F-35 will rise, leading to fewer purchases (and then leading to more cuts in the number bought and hence higher unit costs, for an unknown number of cycles).
So with fewer purchases, do we simply shrink the Air Force or do we try to maintain numbers with a less capable aircraft. If we do the latter, could the F-15SE fill the gap?