There’s still a lot of mystery surrounding the Nintendo NX. There have been rumors of what it is, and what it isn’t. Including that it really isn’t a console, that it uses cartridges, and that the controller isn’t like anything Nintendo has done before.
Well, patents have been surfacing on the web about what the possible NX controller may indeed look like, and as some reports have speculated, the controller may have removable pieces. Thus making it customizable to any who use it. An example is below, and the rest can be seen here on Nintendo Life.
According to the pics, the D-Pads and buttons can be interchanged to better suit a gamers playing style. And there appears to be a Wii U/DS style screen in the center of the controller. Possibly emphasizing either a portable console, or another dual screen attempt.
The NX comes out in March 2017, but things could always change, and nothing is certain until Nintendo gives the official word.