I do enjoy a few of the Sonic games after 06 such as Colors, Unleashed, and Black Knight, but I think the problem with SEGA is that they're relying on Sonic too much.
Let's face it. Ever since the travesty that was 06, SEGA has been doing quite bad with firing a huge chunk of their workers all the time, especially after Sonic Boom, and I can easily see people just skipping out on Fire and Ice when it comes out. And just yesterday I read this article that said SEGA realized their purchase of Atlus may have been a bad idea. They need to get their thing together somehow.