I haven't played them yet, but apparently Sonic Colors and Sonic Generations are supposed to be pretty awesome. Fans seem to consider those games to be Sonic's return to form after his dark days.
Also, Sonic 2 > Sonic 3.
Colours is a vast improvement and the highlight of the franchise since the Megadrive days.
Generations has a lot of nice touches, solid gameplay and good renditions of old maps. But it lacks something to make the whole thing work quite right.
So right now everyone is just hoping this turns out more like Colours, which is looks to be doing.
As for Sonic 3, they really should have just waited another few months and had the full Sonic 3 and Knuckles version with everything ironed out. Then again Sonic 2 has it's fair share of bad ideas and poor gameplay.
The Robotnik thing was for anyone who hadn't played Generations yet, and as of writing the first post his part in this game hadn't been publicised, not on any of the Sega or Sonic websites I'd been to as of Thursday anyway. They better have a pretty good explanation of how he escaped the White Zone then.