Nate is way underselling himself. He's essentially not only acquired most of the contents of most of the app stores, and not only decompiled them, but has then built up a comparative analytics framework that can answer questions based on code similarity (as a first order of available facts) and behavior (as a sort of second-order thing).
I'm really curious to see what ideas other people would have for this kind of data set. If you could answer virtually any question about the behavior of any/every app in the app store, what would you do with that capability?
Also: people should ask him questions about how this stuff works. It's really neat.