There has been an increase in announcements lately regarding the upcoming sequel to Sonic 4: Episode I. The first episode as you might know was a platform video game designed to bring the anthropomorphic hedgehog back to his two-dimensional roots. It did the job reasonably well for the most part, receiving mixed to positive reviews from critics. The second episode is currently being developed by Dimps and Sonic Team for most gaming platforms (except the Nintendo Wii); although an exact release date is not yet known.
Based on recent screenshots and a radical new trailer, the sequel is looking to be pretty good, and the developers have also said in interviews that the controls and physics will be made programmed from the ground up. Hopefully it does end up being a very good game, because there aren't any more episodes being planned it looks like. When interviewed about the possibility for further sequels, producer Takashi IIzuka of Sonic Team had this to say:
But not all hope is lost. The company also mentioned that they were focusing on critical reception and sales numbers, so if you're really interested in seeing further 2D installments from the blue blur, support the team and buy the downloadable game once it comes out. And look! More screenshots! Colors!