As I browsed those screen-shots I noticed the music section and photos section look a little different, but I don't see any significant updates or changes in the UI compared to Visa. Keep in mind that it's early and much can (and should) change between now and the release date sometime next year. Check them out and let me know in the comments if you see anything significant to speak of.
I think Microsoft needs to bring some major new features such as h.264 support, true server client ability, softsled, better online video streaming etc to make it a must-have upgrade over the current version. I like these first looks of the Windows 7 UI, but I also like the Vista Media Center UI.
WinFuture.de (German Website)
via Green Button Forums