Yes, of course, Nintendo are always planning new consoles after their current one launches; it's natural that they look ahead to the future, they did the same with N64, GC and Wii. Right now, they've confirmed only that they've been working on new ideas for their next console and I believe AMD and Sharp could be helping them develop this new console, but Sharp's new screens is most likely geared towards their upcoming Quality of Life devices.
Anyways, a new Nintendo console is being planned but right now we have little details as to what it could be. Chances are, it will be able to play old Wii U games, as Nintendo want to retain the same infrastructure (and it's a great way to implement Wii U's underrated ideas and use it as a marketing advantage) but we'll most likely be waiting a few years until we get definitive details about the system.