It’s confirmed that a new 2d HD sonic is on the way in 2010. The project is called “Needlemouse” and from an interview between Gamespot and Sega of America’s Ken Balough, you can lock it in that Sonic is indeed coming back in an old school way.
“Old-school Sonic fans have long asked to see Sonic return to a more 2D style of gameplay. Many liked the daytime stages in Unleashed, but wanted to see a game that plays purely similar to the early games of the Genesis. Project Needlemouse is that critical first step that brings Sonic back to his 2D roots.”
Check out the teaser: