LOS ANGELES--Microsoft opened the next-generation floodgates last week when it publicly unveiled the Xbox 360 on an MTV special, firing the first shots at its rivals in what is sure to be an all-out war for consumers. The Xbox 360 will be released this holiday season, and Microsoft held its annual E3 press conference today to tout the system's features and show off its planned lineup of games. The event took place shortly after Sony wowed the crowd at its own conference by unveiling the PlayStation 3.

The biggest story of the press conference surprised many attendees at the Shrine Auditorium. Microsoft announced that Square Enix, a longtime partner with Microsoft rivals Nintendo and Sony, will be bringing Final Fantasy XI to the Xbox 360 and Xbox Live.

This will be the first Square Enix game for a Microsoft console, and the third platform for FFXI, which previously appeared on the PC in 2003 and PlayStation 2 in 2004. Final Fantasy XI was the first game in the popular role-playing series to go online, and the Xbox version will sport new high-definition graphics and make use of all of Xbox Live's features.

Along with a firm release date and price point, the other big question surrounding the 360 was backward compatibility. However, Microsoft would only say that the console will be "backward-compatible with top-selling Xbox games." This ambiguous wording could mean that Microsoft will select which titles will run on the next-gen console. However, it could also simply mean that Microsoft is merely being prudent in case some original Xbox titles don't work on the 360, as was the case with some older PlayStation 1 games and the PlayStation 2.

Although future Xbox 360 owners will be able to play the more than 200 Xbox titles expected this year, it's the 360 games that they'll really want. Microsoft expects 25 to 40 Xbox 360 titles to be available during the console's launch window (defined as within three months of the system's release), and developers currently have more than 160 games in the works.

Among the games Microsoft announced for the console were Tecmo's previously unrevealed fighter Dead or Alive 4 and Capcom's zombie-slayer Dead Rising, which is being developed by legendary game designer Keiji Inafune.

Publisher Electronic Arts announced that its lineup of 360 games, which includes Madden NFL 06, Need for Speed Most Wanted, and The Godfather, signifies its largest commitment to any next-generation console's launch.

As detailed last week, Xbox Live will come in two different packages. Xbox Live Silver, which allows gamers to send voice and text messages and participate in other basic features, and the premium subscription-based Xbox Live Gold package, which includes spectator mode and multiplayer gaming privileges. It turns out anyone with an Xbox 360 will get a taste of the good life. Microsoft today announced that all 360 owners will be treated to a free month of the Gold service when they first jack into Xbox Live.

GameSpot will be updating this story and will have more details on Microsoft's E3 press conference, including video and photos, very soon.