Sega has made the rumoured PlayStation Network and Xbox Live Arcade release of Sonic Adventure 2 official.
An announcement was made at the Sonic Boom event during San Diego Comic-Con over the weekend. A video of the announcement, accompanied by a trailer, is below. Warning, people make a lot of noise.
Last month a listing for the Dreamcast game briefly popped up on Xbox.com. It revealed a 3rd October release date, offline multiplayer, content downloads and leaderboards. Screenshots suggested it was an HD upgrade rather than a port.
The first Sonic Adventure was re-released on XBLA on 15th September 2010 in honour of the Dreamcast's 11th birthday.