AT&T has announced that it would be the exclusive carrier for Dell’s first smartphone to be launched in U.S. The phone is apparently called the Mini 3, which was selling only in Brazil and China since last year. AT&T would be finally be joining the Android arena.

The release date, specs and pricing info was not announced, but the specs on the device would be similar to those on the existing Mini 3, which features a 3.5-inch display with 640×360 screen resolution, 3-megapixel auto-focus camera with flash,  Bluetooth, GPS and a microSD storage slot.

Along with the Dell Mini 3, it also has plans to launch at least four more Android phones in 2010, one made by Motorola and three to be manufactured by HTC.That puts an Android lineup on all the major carriers in the States.Google’s platform continues to boom.