Two things to know :

Vita will have very bad sales for the 2 weeks coming, everybody waiting for the cut price in the world the 28th.

Vita could outsell Wii U, its easy cause Wii U have less big exclusive games coming ( only Lego City in march, after, we dont know when Bayonetta or Wonderful 101 will come ) .
But at the end of the year, Wii U will have mario, Vita could have 10 exclusive games but people dont care, because only a single mario is better than anything as a system seller, the only game which will bring casual + kids , what Vita have not ( TearAwat looks amazing but its not enough famous ).
So at the end, Wii U will outsell Vita, but its good if Vita keep beating Wii U until Mario.

Ok guys Wii U will have 'another Mario game' (quoting Sony here). But it might as well have PS4 and 720 launched by that time.

Is Mario that powerful? Can it push Wii U against all odds and all next gen hype? Will the Wii U pull a Gamecube or a 3DS? That's what I am curious to see. Competition matters a lot, we must not forget Wii U will have the real competition out soon.

Look. I agree with you that 3D Mario is much better than 2D Mario. I enjoy it much more and I couldn't care less about NSMBU. But that doesn't change the fact, that the general public loves 2D Mario and doesn't care that much about 3D Mario. It's a fact and sales prove it. If the release game was a 3D Mario, it would be even worse for Nintendo than it is now. 2D Mario and Mario Kart are the two ultimate system sellers, the best in history. 3D Mario is good, but can't even be compared to these titans.

If you align the launches of Wii U and Vita, Vita sold 53% more consoles in its 11th week than Wii U did in its 11th week. It is doing worse than Vita was doing at that point.

Although Wii U sales have been slow, the console is just beginning and Nintendo has a huge list of games to be released over the next few years that will sell consoles by the truckload. As for the Vita, I think it will keep selling pretty much at the rate it is currently. Sony is focusing most of its attention to PS4 as are Sony fans. Wii U will double Vita sales in 2013 in my opinion....

As I already said - it's the other way round. Vita has good games coming in the next weeks and months, all strenghtened by the price cut. Wii U has very good games announced, but most of them don't even have a release date and some of them probably won't make it in 2013. That is a huge difference. Vita games are ready, they are about to hit the market and hopefully ignite the sales. Wii U games are far from it and until a game lands on the shelf, it won't sell a single console.

Just compare the games that actually have got release dates and Wii U looks bleak in comparison.

Second rate 3rd party games, re-releases, and abismol 1st party games won't sell Vita. Let's be realistic, majority of what's coming for Vita is like shovelware/games that won't get very far past release. At the very least, everything on the horizon for Wii U (first party wise) will be top rate games that actually do sell units (separately and with bundles) and most likely go over 1,000,000 sold. Most of the games coming for VIta will be lucky to crack 300k - 400k.

Let's just try to be realistic when trying to support Vita. Okay? 

Youre not realistic, just pessimistic supporting Wii U over Vita.

Vita has big games coming and many famous games, and soon, especially in Japan, with the price cut, the sales will be good for these 3 month when Wii U will have to wait, selling 30k each month till  the end of the year for Mario. ( the only game we know for this year which could sells unit and make it outsell the Vita, and maybe Pikmin but Pikmin isnt really famous, the sales decreased since the first )

Many potential Wii U buyers are just waiting for the game they want on the Wii U. So I only see the Vita maybe outselling the Wii U for 2 and 1/2 weeks. Then, March 18 happens and 7 Wii U games will be coming in that week as well as Mother 2 coming out in Japan

Do you even have the slightest idea of what games are coming to Vita? Your disrespect for these titles is disturbing, as many of them are easily AAA games. You really sound off as a hater and not a realistic person.

There may be no no-brainer system seller that will sell 4 millions among these titles, but they are great games and they are much better than the big fat nothing that Wii U is getting over that same period. Vita is getting really good games in the coming months, combined with the price cut that will improve sales. The big Wii U games may not even come this year, and even if they do come out on Christmas, they'll be crushed by the release of PS4 and X720. By that time Vita will be far ahead of Wii U thanks to this "second rate shovelware" that actually got released in the course of the year and not just announced like the Wii U games. Do you really see that as such an unrealistic scenario?

I'm not saying it has to happen, the race will most probably be a close one (unless Vita suddenly explodes in Japan), but this is a possible turn of events. And I'm going to repeat - we're talking just about 2013. How many of these system sellers you talk about will Nintendo pump out this year, if even Pikmin 3 hasn't got a release date yet and it was supposed to be a launch window title?

Well, you can't judge a console that has just come out 4 months ago. There haven't been any blockbuster games out yet believe it or not those type of games take time to make. A lot of time. I don't think 3D mario will do horribly seeing that most gamers, I would hope, like to see improvement and variety in their games not the same old thing. I know 2D mario is more popular than 3D mario because that's what early Nintendo adopters played back in the late 80's and early 90's. Now chums can play 2D mario side by side like the old days, what gamer wouldn't want that? On the flipside I honestly can't wait for the new Mario Kart and 3D mario.