“SEGA has announced Sonic 4: Episode I. It is, as GameSpot reports, a 2D downloadable game with 3D visuals.
The announcement is part of the Project Needlemouse build up SEGA has been pushing since last September 2009. “Needlemouse” refers to Sonic’s codename when the game that would become Sonic The Hedgehog was initially being pitched.
While teasing [...]

“Sega teases “Project Needlemouse” which seems to be a High Definition 2D Sonic game for 2010. Sega has also just put up a teaser site.”
Sega Announces Brand New 2D Sonic for 2010 (via vgchartz.com)