Yes 1 game makes a difference but it is not the whole story obviously.
I mean everyone noted W101 was sent out to die, but Nintendo was just riding their plan, that is add this types of games (like W101, LoZ WW HD, etc) to make the library and the system more enticing and varied. It is certainly paying off big time because I imagine a new buyer goes
"ok I want SM3DW but just one game, then looks at the library, game recommendations and there is W101, Pikmin 3, LoZ WW HD, some nice local MP party games, some 3rd party standouts". All of a sudden you got your killer app next to some other well crafted games it is a no brainer. I hope the Wii U turns it around!!
I am a kid again, playing with my 8yo SM3DW. Best highlight of the year IMO.