I think it's more a case of it being pretty easy to implement, so why not?

I mean, with all the assets they're sharing with the 3DS version, they're practically the same games when running. I'm sure they're using the same character models just with higher res textures. That's a lot of leftover power on the Wii U, and it probably wasn't too difficult to get it up to 1080 at that point. Besides, the higher resolution does generally benefit fighting games in a way it doesn't benefit many other genres.

This is beyond epic... Probably the best looking fighter right now...

Only fighter that looks better than this is probably KI for the Xbone.

Ubisoft: "Should have made it 900p to stop all the debates. And 30 fps to provide the best cinematic experience"

Uhmm... the PSOne was just a smaller PS1. It wasn't designed to do 1080p and 60 fps.

But if you're referring to PS4 and X1. They do and more often.

My first thought was that maybe they just brute forced it for the hell of it (it's a fighting game after all, the WiiU would have a lot of room left at 720p/60fps), but seeing as NSMBU was 720p, i can see why you'd be curious... if they could brute Smash, they sure as hell could NSMBU.

I wonder if maybe they thought it was necessary for the 8 player mode to be enjoyable? 8 players with the camera zoomed out could get pretty disorientating at 720p. Having lots of small on-screen objects to track is the perfect example of a time when 1080p can be a huge benefit (rather than just standard clarity).

I don't trust playeressence ...

The site has a reputation as a haven for some controversial promotion for Nintendo and I find it extremely strange they're the only ones that reported this but not only that, playeressence is a low tier gaming site so I doubt the reps at Nintendo would give them their time of the day too.

Yeah, I'll wait on Digital Foundry's analysis before jumping into a bandwagon that might end up getting crashed ...

Well to be fair,it's a 3ds tier game.

Don't expect 100k polygoned models or something like that

In think it could potentially be a variable 60fps or locked 30fps in some situations (depends how much time they spend optimization the game around the 8 player mode), but i'd be surprised if the standard 4 player mode wasn't 1080p/60fps(locked). They've confirmed it's 1080p, and Smash has always been 60fps, so it seems likely.

Give me an actual link where we see Nintendo confirming this. 

Playeressence is the one of the most fanboy Nintendo site on the internet, you can even get banned for saying something remotely negative about them.

They "confirmed" that MK8 was 1080, 60fps, that's their credibility.

Still, I do remember Nintendo announcing this when the game was first unveiled 2 on E3 2013.