Well, I said "a look into Rayman's creation and past", but that's what Rayman Origins is for.
I'm still sticking by the idea of returning characters, both good and bad.
Mr. Dark's return... that could prove to be a very good plot element (I've already mentioned that, haven't I... DOH!)
Rayman should be able to use all of his powers this time, as in both fists and energy balls (think how they did it in RRR DS, but with charging and no limits).
So... yeah. I'm leaning towards a Rayman 4 that was similar to the fan game I had originally wanted to make, but as I am not really into GameMaker anymore my fan game ain't gonna happen. I was working on an artwork for it, though, so I'll finish that!
Rayman 4: The Darkness Returns! I definately would go out of my way to buy that!