I've just stated playing Mario vs DK 2. This one was done entirely by Nintendo of America, right?
I reckon these guys should make the next Mario Platformer in this exact visual style, with the same characterisation, powerups, mix of enemies etc. It would completely rock, and be just the right mix of nostalgia and new ingredients.
Personally, and I know I'm in the severe minority here, I have always hated Super Mario World. Graphics are terrible, gameplay is even more convuluted than Toki Toki Panic, enemies are stoopid, rendering and illustration is poor (are those fat ball things meant to be goombas or what??). I would be very disappointed if any new Mario platformer took its cues from SMW.