I E-Mailed BJ Charles, Manager of the project. I can’t say much, but I can say that a publisher is trying to be found to get this title on a Sega system. If it becomes a reality it will be unprecedented; this game will become the first Sonic game on a video game system made by fans (not a “fan game”).
To recap, Sonic 4 was originally called Sonic 2 Gold, but the team got a letter from Sega stating that the beta levels could be kept, but finished levels could not. However, the project would continue. And from the details I’ve received, this could rival the Sonic Robo Blast series greatly.