Xbox 360, besides World of Tanks, is getting a free-to-play title coming this year and its name is Warface. Developed by Crytek, the shooter has announced that today begins the beta on Xbox 360. Sign ups here.
The game is free-to-play, but you NEED an Xbox Live Gold subscription in order to play it, so not really 100% free-to-play. The beta is live for the following countries: United States, Canada, Mexico, United Kingdom, France, Italy, Germany, Spain, Nordics, Australia, and New Zealand.
Thanks Xbox News for the information. Be careful of this game, as the gameplay footage above shows spawn trapping and camping are very likely in this game.