Microsoft have revealed that they plan to introduce the LIVE and Zune services to Windows Mobile. In particular they had this to say on the LIVE service:
This hub delivers the first and only official Xbox LIVE experience on a phone, including Xbox LIVE games, Spotlight feed and the ability to see a gamer's avatar, Achievements and gamer profile.
Gamers will be able to play games and earn achievements and developers will also be able to write games that will work on a mobile as well as other platforms such as Xbox 360.
Source - xboxresource.com/viewurl.php?u...