Eurogamer: Nintendo NX is a portable console with detachable controllers (It also connects to your TV, and runs cartridges)

[Soundwave]

This guy is saying it has two controller units, not sure if they attach together.

Really could be a much more modern version of this:

x1000000000000000 of course. 

That would echo a lot of the DS design principals, because Yamauchi chose 2 screens for it echoing the past Game & Watch line.