Rather, the 360 version of Silver06 was rushed to the market.
Yeah, it really had a rushed three and a half years...
There is never going to be a PlayStation 3 exclusive game, especially when Sonic games do significantly better on Wii, DS and Xbox 360 platforms.
And remaking old levels is bullshit. Just do not do it, especially with Sonic Team. Remake some of the music if you want (try not to make it all guitars though!) and we'll see. If they did some of the 2D level, they would turn out terrible like the ones in Sonic Colors. Something like City Escape as Dr SEGA Monkey pointed out though would not be bad at all, but... Basic cities are really overrunning the franchise. What ever happened to the cool art from Speed Highway or Star Light Zone?