Thanks for the answer!
My problems with the original NSMB are just a few. I don't consider it a bad game, or mediocre. It's good. It's just I expected more from Mario. It was very short and easy (I completed it in a single playthrough, I put the game, I played some hours, and it was gone). And I found the music lacking what I like to have in a Mario game in musical terms.
But it's not Sonic Colours, don't get me wrong (I know, now someone will say they liked Sonic Colours...).
If there are some elements of Galaxy in 3DLand I will enjoy that, for sure. I liked everything in Galaxy, with the only exception of some random mini games that I found out of place.
I liked Galaxy 2 better, though.
If the new game for WiiU focus on multiplayer chaotic kind of gameplay, I will surely be bored, since I like to play alone anyway, and I don't enjoy chaotic multiplayer.