I've been avoiding this topic all week because I feel it's an interesting question that could go either way, but I've plumped for Splatoon. Looking at the kind of stuff that has really sold on Wii U it seems to fit the bill far more than X with its fast-paced, colourful action. Probably fairly close though. I will be getting both, providing they turn out to be top-quality games.

I believe that XCX will be more successful. Splatoon has a few missing key features that might keep potential customers away.

It's difficult to say. On one hand, Splatoon has that Mario Kartish quality of being both complex and simple in a way that allows for broad appeal. On the other hand, Xenoblade Chronicles X has more traditionally mainstream aspects: its open world, the combat, the SciFi setting the art style (character models not withstanding), the online functionality. SciFi open, open world, and RPGs are pretty big right now. So they both have their strengths.  And if there's a price cut to the Wii U, it gets even more competitive.  And I am not sure which game would benefit more from that price cut.  

Xenoblade X is a far more ambitious game and leagues ahead of Splatoon in every aspect. I do hope it'll sell more, or it will mean that the WiiU audience doesn't want AAA games.

Xenoblade. It has a lot to live up to and it is a very impressive looking game. Splatoon, I think, is just too far of that Nintendo train to sell really well. It's a new franchise, Wii U already isn't selling that hot and it doesn't really seem that impressive to me. It's new, I'm with new. But I don't think it has the stuff to outsell XCX.

Xenoblade should be able to do 1mill but I don't think splatoon will cross the 500k mark

i think he is trying to say that XCX needs to be ported to ps4 and xi in order to be succesful ( which i disagree... if anything, this game is getting way more atention for being an exclusive). Not really a port begging. Again, i think...

I want Sly or R & C on the Wii U. :p

And Banjo and Conker.

If that was his intent, then I disagree with that also.

If this game manages to sell 1m+ LT (which I think it will), then it would be an automatic success imo. Going from around 900k on a 100m userbase to 1m+ on a 10m userbase would be outstanding for the franchise and would encourage Nintendo to continue it. I'm certain that they were cautious of spending when developing this game so that would equal a notable profit as well.

Simple really; we're fussy as hell. I mean,  we lean towards a console known for making up for 'not having a quartor enough filler' by having an undue amount of the best games of each generation. Its no wonder we can't agree on Nontendo games worth adding to the mix.