...But, according to this rumor, they'd be supporting Nintendo's console this time, the Wii U.
As it is, presumably there'd be one version of the game developed for PC/PS3/360/Wii U, which is down-ported to Vita, and up-ported to Sony and Microsoft's next console (better framerate, higher polygon models and visual effects, etc). Assuming it's Hedgehog Engine, they pretty much need a second, different game developed for the 3DS, since it presumably can't handle the Hedgehog Engine. Enter Dimps, who'll throw together something. So that's at least two different games being developed with the same name.
We know they're not interested in getting the Hedgehog Engine to work on Wii, or they literally can't, so they either have to make the Wii version be a port of the 3DS version, or they have to develop a completely separate, third game just for the Wii, which will be a very budget-minded console at that point. And there's plenty of budget Sonic titles on that platform already.