Like:
Sleek design
Zelda and new Mario looks amazing
Combined installed base means less droughts due to avoiding bifurcating development efforts
Actual smart hardware choices this time around
Seemingly good performance if the rumored specs are more or less correct
The fact that they finally showed the damn thing!!! 
Dislike:
Tablet form factor, I'm really not feeling that this a smart move all in all
Seeming focus on the handheld bit, I have zero interest in handheld gaming, never much liked it
Controller schemes look kind of half-baked and not very ergonomic
Little to no news on multimedia capability and connectivity
Continued focus on local multiplayer means likely less focus on proper online, which is sorely needed
Honestly; I'm not loving it and I can't see this being a huge success in its current (and likely finalized) form.