You've struck me with awe. The visual style is even better than what we have now. The threaded/flat view is great: it's threaded while looking flat. I think a lot of flat-fans will be happy. The reply-popup (instead of opening a new page) is so useful:
sometimes when replying, I need to go back to view some posts I was replying to. This is more than just screenshots, it's a cool presentation.