Well, I'd say that on the bright side, WiiU tried to reinvent itself rather than just blatantly be a Wii 2, for better or worse. It had cool gimmicks, like the ability to keep playing even if someone wanted the TV, and some great games overall, like The Wonderful 101, Smash Bros 4, Bayonetta, Devil's Third, Pikmin 3, Fatal Frase and the upcoming Tokio Mirage Sessions (which is shaping up to be good, despite the censorship), to name a few. It also had decent third party support, albeit worse than Wii's.
On the not so bright side, we have an underperforming console whose legacy will definitively taint NX to an extent, and Nintendo's reputation on the market. Say what you want about Sony and Microsoft, Nintendo has been kind of a disaster with the WiiU, more than a virtuous competitor. Not only we have more disatisfied consumers like ever in Ninty's history, we also get a track record of some really horrible treatment to classic IPs (like Animal Crossing), some horrible droughts that relied on nothing but blind hope to get across (or owning another console, yeah), and the fact that the console only lasted a bit more than the original Xbox while arguably having the same (or less!) support overall.
Not a good heritage, to be honest. NX has a lot to prove.
