Maybe I'm being naive, but...
I've seen a lot of people, nay, NINTENDO FANS on this thread say "Oh, this may be the first Mario platformer that I pass on."
Now, in retrospect:  Has there ever been a Mario platformer, in the history of Mario platformers, that have been bad enough or even mediocre enough to pass on?  I'm ignoring the Lost Levels, but hey, I'm American and I was never given the chance to pass on that, in Nintendo's finite but sizeable wisdom.  
The decison-makers at NCL are not stupid, and as much as making a mediocre sequel to cash in might sound plausible or even likely (hello Activision) I have a little faith that this will be a good game with inspired level design, at the very least.  At the very, very worst, this will be NSMB DS, and hey, we knock that game, but it was enjoyable.   I bought it.