Not really. Vista's media center works pretty well already, so most of the changes are evolutionary. They have gone through like 5 versions of Media center already too (XP media center 2002, media center 2003, media center 2004, media center 2005, and media center for vista).
Microsoft's site has some pictures of Media Center for Vista: http://www.microsoft.com/windows/windows-vista/features/media-center.aspx
Has anyone sucessfully used an XBOX 360 as an extender with Windows 7 as MCE, I can access media on the W7 computer but I can't get MCE to run, it says it need to connect to XBOX LIVE and I can't do that until tomorrow as I updated my XBOX to the new firmware.