Played through the first 2 worlds, and yeah it's fun... but I can't seem to shake off the "more of the same" feeling. Maybe it's just because I prefer 2D Mario or something...
But the new additions, with the exception of the Cloud Mario, don't really work for me. I hate controlling Yoshi when he has the Speed Pepper (reminds me of playing a 3D Sonic with the erraticness of it), and was disappointed to find out that some waggle minigames were back in. I'm gonna keep playing, get all the stars, of course... but with all the praise on the game, I expected a bit more.