I think that all they do now is to gather "user experience" data and test what they have at the moment of a Panda "update". It's not really an update but a test with what they have so far. For every "test" they collect more data and they will keep doing that until they find a balance between their stuff and to show some sites in the serps.
I think we can try to figure it out, but if we don't know what data they collect and how it is used, SEO is dead in the water. I think we can try to change whatever we think is right, but we'll never "get it right" according to Google. It wouldn't surprise me if they read this board (Hello Google!) just to figure out what we are up to and how we can "fool" their algo. I don't think Google want us to do SEO. They want to decide for themselves who is supposed to be on the first page.