According to IGNDC, SEGA actualy has a secret game in development! Take a look at this article:

In the latest issue of Denki magazine, it was reported that Sega is currently working on a secret project which is due to be announced next March. According to the report, it's rumored that the game will actually be an update to one on Sega's previous consoles.
Sega Japan has made no official statement on the matter to date, but considering the game would only be in planning at this stage, we wouldn't expect it to. So, anyone up for a Dreamcast version of Shinobi or Golden Axe?

It's possible that SEGA is trying to bring some of it's old legendary titles to DC. Also, do note that, sinse the game is rumored to be an update of an older format, it is possible that we may see something that many Sonic fans out there tenaciously ask for. Can you say Sonic Jam 2 kiddies? Only time will tell...

You can see the original article here.
Source : IGNDC