http://www.eurogamer.net/article.php?article_id=78437
Shadowrun and Halo 2 - the first champions of Windows Vista gaming - have already been cracked by warez and hacking groups, with patches enabling both to function on Windows XP flying around the Internet
First [Microsoft] claim that it was impossible to implement DirectX 10 compatibility atop Windows XP, and now they also want us to believe that they couldn’t successfully launch two DirectX 9 based titles on XP either. We plan to expose both theories as patently false."
So far it appears that Vista has no more functionality than XP still
