A German web site has posted 18 screenshots of an interim build of Windows Vista. This build shows vast improvements to the desktop UI as well as improvements to Internet Explorer 7 and the login screen.
Not much is said of the performance or other changes, but one can expect that to be dramatically improved due to Microsofts own announcement of build 5365, to be released to testers on monday. There they announced 'major performance increase' and 'better driver support' updates on that, to follow.
News source: Win-News (German)