Super Mario Switch aka Super Mario Sunshine 2 but with a Map Screen, Level Select a la Mario 3.
The Mexican looking area in the Switch snippet is actually another Pianta Village, they will remaster the first game release this first and give Super Mario Switch extra development time and release Xmas 2017.
I loved Mario 3D World, in some ways more than I loved the likes of Galaxy/64 so wouldn't be disappointed if the game ends up more like that. However, judging from the early footage it does look to have more in common with 64/Sunshine. To be honest I trust Nintendo fully on this one, don't think the Mario series has ever really taken a major misstep in terms of the main games in the series.