As I have before, I think that increases in computing power may have the effect of making stealth less effective.

Well, Wired has an article about a new and very powerful algorithm for imaging, called compressed sensing, which uses the simplicity as a way to enhance images, the example they give is a non-military one, specifically the need to image the bile ducts of a small child to see if they were blocked, which required that he be heavily sedated and that his ventilator be shut down so as to keep him still.

With conventional imaging, it would take over 2 minutes and risk brain damage to get the resolution required, but with the new algorithm, it took only 40 seconds.

While this is an interesting possibility for many areas, I can see how this technique, when combined with data from multiple sensors could give a high resolution solution for an air defense system.

In fact, going around the web, you see examples of single pixel cameras producing decent imagery.

These guys see the primary application being low power, and non visible light, where massive arrays become impractical, but I think that military applications will come, and anti-stealth is a likely direction.