Give me one example of a mobile game that has better or equal gameplay to NSMBW.
Plants vs Zombies? Equal gameplay? What kind of metrics are you looking for in gameplay? Controls, physics?
Trine seemed to have reasonable gameplay. I can't say it's equal but it's certainly comparable. Mind you that's a steam/XBLA game.
The controls issue is being worked on in the market, there are ways to connect a dualshock to tablets and smartphones, it will become a reality where mobile games can easily be played with more traditional forms of input.