Agreed with a lot of posts on here, what Nintendo really need is performance parity at a minimum with preferably a more powerful system than X1 and PS4.
Nintendo games are great, if the system was powerful enough it would allow those games to really shine and wow people, and third party's could bring multi-platform games to Nintendo hardware as well. A superior version would be even more enticing, more people would then be willing to make the jump, rather than just the current Nintendo fans, which are dwindling if you look at the stats (The Wii was an outlier, the general trend is downwards since the NES / SNES).
Graphics / performance is important, as the constant debate about with X1 and PS4 owners already shows. Nintendo having the gaming prowess, now just match that with great hardware and people would pony up the cash for a new console imho.