The recent Trend in Games seems to be 2d style platforms performed on a 3d platforming world. There are events going on in front and behind, sometimes affected by the player, sometimes just background noise.
While I was never a big fan of Sonic, having played only the first, I do appreciate its niche market on the race your character really fast around the screen and set off cool explosions and screen affects IF you manage to have the right speed and right knowledge of the level..
Akin to Prince of Persia: Warrior within. If you knew the map, and could play it through without mistakes and it was wonderful to watch, I think that was the beauty of Sonic which is what they should try to re-achieve.
So the new faux-3D platformer genre thats coming out might indeed be a Sonic friendly genre. Lets wait and see.