And yeah, like Slime said the original games required INSANE precision, moreso than any other game off the top of my head. Navigating wirethin floor while making 90 degree turns and pulling off crazy cheat jumps (which were there are on purpose) depending on having an EXACT movement.
Despite the "lol, rolling = tilt = let's throw it on wii" mentality that doomed the franchise, The Wii is probably the WORST possible fit for the type of game SMB1/2 were. Hell even the PS2 version of SMB1+2 was almost unplayable because the analogue on the PS2 stick was not accurate enough.
Best system for a legit new SMB would be X360. The PS3 analogue is not up to task, the Wii nunchuck is stuck with the hexagon and not up to task and the portables....no.