Nintendo has shared their Nintendo Switch Super Bowl LI commercial on YouTube and it is a good one. The commercial effortlessly gets across the point the of the system by showing how it can be played in a handheld mode and also a home console mode. The commercial features a song by Imagine Dragons and features gameplay from Breath of the Wild.
https://www.youtube.com/watch?v=ZUDkrkykvZs
There is also an extended cut of the commercial that shows as Arms, 1, 2 Switch, Mario Kart 8 Deluxe, Ultra Street Fighter II and Splatoon. This one is about a minute longer.
https://www.youtube.com/watch?v=CdWd8fUC71g
These are excellent ads and Nintendo is showing that they have learned from their mistakes with the Wii U. With marketing on point like this, hopefully the Switch will sell well.