Very little to go off here, but it looks aces.
Seems to me like they've melded the tight obstacle-course emphasis of the 3D games with the older more adventurey formula, which sounds like a great combo.
One of the best things about 3d Mario games is that they're always striving to evolve the broad concept while iterating what works on a micro-level. We had two 64 style games, two Galaxy games, two 3D games, and now whatever this new thing shakes out to be, which I'm sure will be as distinct as the previous three formulations.
As a bonus, the Mexi-world we see here would seem to signal an aesthetic shake-up, which is always good news. I thought 3D World looked great for what it was doing, but I'm happy to see Nintendo broaden the pallet here, especially after the understandable blandness complaints stemming from the NSMB games. It could be pretty awesome if the different worlds take different world cultural themes. Sunshine was pretty narrow in focus, but I liked it's vibe, especially the later night-time tropical village world.