The first handset supporting Windows Phone 7, the HTC 7 Mozart, will launch in the UK on October 21 and the US on November 8.
Windows Phone 7, which Microsoft describes as "a new and major games platform", will ship on nine phones across 60 mobile operators in 30 countries this holiday season. Handset manufacturers include Dell, Samsung and LG.
Confirmed Xbox Live features are avatars, friends lists and achievements. Games are purchased through the Games Hub, Windows Phone 7's AppStore equivalent, and allow game invites from other users.
EA is bringing Need For Speed Undercover, Tetris, The Sims 3 and Monopoly to Windows Phone 7 handsets, while Gameloft, Konami, Namco Bandai, PopCap and THQ are also confirmed to support the platform.
"Together EA and Microsoft have created some of the definitive console games of this generation, and we're excited to bring that powerful alliance to Windows Phone 7," said Ron Pessner, general manager of Xbox Live mobile. "This is a new and major games platform for Microsoft, and we look forward to the amazing games EA will deliver over the coming years."
Travis Boatman, EA Mobile's VP of Worldwide Studios, added: "We see consumers deeply integrating devices into their lives and entertainment in new ways every day. Challenging your Xbox Live friends to an EA game from the phone in your pocket keeps you connected and having fun no matter where you are."
Yesterday Microsoft said it views its upcoming Windows Phone 7 platform "as a games console" and plans to support it with a robust launch line-up of titles.