The Dreamcast sequel was spotted with a listing on Xbox.com claiming the digital release will feature leaderboards, future content downloads and local multiplayer.
The listing, which was promptly taken down, also suggested a release date of October 3.
Users on NeoGAF captured images of the Xbox.com listing, which bizarrely features a PlayStation controller button prompt in one of the screenshots.
The mix-up may be the reason for the listing's removal, and indicates that the game will arrive as a download on PlayStation 3 as well.
Sega has increasingly been dipping into its Dreamcast library to produce HD ports for Xbox Live Arcade and PlayStation Network. Past HD releases have included Sonic Adventure, Crazy Taxi, Space Channel 5: Part 2 and Sega Bass Fishing.
A HD port of Jet Set Radio will also be released this summer on XBLA, PSN and PlayStation Vita.
The publisher has also hinted that ports of Shenmue and Skies of Arcadia could be on the way in the future.
Sonic Adventure 2 originally released on the Dreamcast in 2001 and introduced Sonic's rival, Shadow, while allowing players to go through both light and dark storylines.
It received a port on GameCube in 2002 titled Sonic Adventure 2 Battle which featured enhanced multiplayer modes.
Watch a gameplay video from Sonic Adventure 2 below: