The guys over at WMExperts have gotten their hands on what appears to be a mockup of WM7. WM6.5 is on the top with the WM7 images on the bottom.
If this is real, it looks as though Microsoft is finally making progress on making WM more finger-friendly and making some cosmetic changes to the GUI instead of just making everything large and ugly (like some of the leaked WM6.5 have looked).