Nintendo confirmed to Famitsu that the Switch would not support physical media from 3DS and Wii U for backward compatibility.
This will make the Switch the first Nintendo console since the GameCube to not offer physical backward compatibility. Famitsu also managed to get some more interesting details that can be read here in Japanese or here on Perfectly Nintendo in English. They also commented on the battery life saying it would be revealed at a later date.
While it is great that Nintendo is looking forward here, one hopes that there’s the ability to play games digitally at least from the Wii U.
Nintendo Switch is expected to be released in March 2017.