It looks like that Sonic may be receiving the new gen treatment and coming to the PS4, Xbox One and Wii U, at least according to a sign that was apparently on show at the Nuremberg Toy Fair which is taking place until the February 3rd. Now this is as of yet unverified so take it with a pinch of salt, but considering Sonic has been making appearances for over twenty years across generations it isn’t unlikely.
What kind of Sonic game could announced varies from a new Sonic Racing, a potential follow up or a game similar to Sonic Generations. It could even be Sonic 4 Episode III, though that would be a surprise as it depended on the sales of Episode II.
Source: All Games Beta

flatspikes
Hmmm
Yorozuya
Hopefully something similar to Generations but much more improved. Sonic 4 was horrible. Love Sonic but it was just way off, they should’ve just did something like Rayman Origins.
Kennykazey
Probably a spiritual successor to Generations, the studio has to do something.
But Sega, Y U NO Jet Set Radio?
ron_mcphatty
I really enjoyed Generations, if they could squeeze more out of that formula I wouldn’t mind at all. It didn’t work so well in 3D though, great when you stood still but as soon as you started moving the paracetamol had to come out!
sparkyscrum
This was rumored on the Sonic sites after the release of Generations. Rumor was that it a reboot of the franchise although I cant remember if it was 2 or 3D.
Sure they mentioned a 2015 launch back then to much disappointment.