Sonic the Hedgehog 4 is not being made Sonic Team or any internal SEGA studio, it's been revealed. The downloadable return to the series' 2D roots is instead being developed by Dimps, which made the Sonic Advance and Sonic Rush games.
Dimps has plenty of experience with 2D Hedgehog games, having made the three-strong Sonic Advance series for the Game Boy Advance and Sonic Rush and Sonic Rush Adventure for the DS. It also co-developed Street Fighter IV with Capcom and has made a ton of Dragon Ball Z games.
It's a logical choice, if still a little surprising to see an external developer take on a banner entry in the main Sonic series. But it's not the only unusual tack taken by Sonic 4 - the game will be released as downloadable episodes on PSN, Xbox Live and WiiWare starting with Episode 1 this summer.