Nintendo usually support their consoles for a long time and there's already a decent catalogue of games for it so you should be fine to get a few years out of it.
Its had great sales, has some cracking games and the hardware is good. So definitely not a flash in the pan. My son loves his ones and uses it all the time, not just for gaming.
Got a couple of them (a normal and a lite) they seem well built but the games seem expensive to me, mind you this is in the days of cheap initially games then having to subscribe to get the good stuff.
We still have the original Wii but skipped the Wii U but I think that was a bit of a Gamecube, where the switch seems to be doing OK if not on PS4 levels of adoption.
They do need to sort out the Netflix situation though.