Played the full version of Sonic 4 today at SEGA, it's absolutely stunning. Saw almost every level, the casino and labyrinth levels are really really good and it looks very nice. There are a lot of recycled things from the old Sonics though. But in general the game has come great. Looking really forward to wednesday.
(Also played Sonic Colors, liked that very much too. I think I will buy it, even if I hate playing on the Wii. The wisps are very nice, they are a really cool new feature.)