Vita 40 million
Wii U 50 Million

Wii U: 50-55
Vita: 60-65
Handhelds seem to sell better. Wii U will sell well in the end.

The DS never needed Pokemon. Nintendogs + Brain Training + other Touch Generations titles had a huge impact on the DS as did New Super Mario Bros., which for a lot of people was their first new 2D Mario since SMW 15+ years prior. So there was a lot of pent up nostalgia (NSMB2 is just "another game"). 

3DS is actually decelerating year over year in the US NPD, it's down this year for both January and February despite having NSMB2 and a new XL hardware revision. 

DS used to clear 400k-600k in a non-Christmas rush month no problem in the US, the 3DS is wheezing like a fat kid trying to get up the stairs when it gets to just shy of 200k a month. 

Nobody but kids and a very, very small subset of "hardcore gamers" (who make a lot of fuss on message boards, but barely register as a blip in actual sales) want dedicated handhelds in the West anymore IMO. The market segment is undergoing a massive reduction. 

Look at the handheld market just 4 years ago ... 

Feburary 2009 NPD

Nintendo DS - 588k

Sony PSP - 199k 

Lets fast forward to Feburary 2013 .... 

Nintendo 3DS - 195k (approx)

Sony Vita - 50k (approx)

It's not like Nintendo hasn't thrown a ton at the 3DS already. $80 price cut, XL hardware revision, tons of different colors, Super Mario 3D Land, New Super Mario Bros. 2, Mario Kart 7, Kid Icarus, Nintendogs, Zelda: OoT, Resident Evil (x2), Super Street Fighter IV, Kingdom Hearts, Paper Mario, Fire Emblem, etc. 

I quoted Superchunk because I was pretty much going to write the same thing.

For Vita, I don't think it has much hope as it stands.  It's too powerful for its own good and doesn't offer any truly compelling games for the mass market.  Sony doesn't have the 1st party games to move it and 3rd parties don't want to put their games on it because it doesn't have a big enough user base.  The price drop will help, but there is still little reason to buy it.  Smart phones are better options for the non-game uses of Vita, and that will only become more pronounced.

I will say 20 million for Vita, unless/until an experiaVita is released, which could do quite well.

For Wii U I also think it is too early to make a valid prediction.  We don't know:

-Nintendo's big games.

-Significant third party support beyond watch_dogs, AC4 and RE: Revelations.

-The price difference between Wii U and NextBox/PS4.

So, in the best case (for Nintendo) scenario, Mario 3D, Zelda HD, X and the Retro project will look outstanding and appeal to the core market, WiiFitU and other new titles will capture some casual customers and some other AAA third party titles such as GTA and Destiny will appear on the system.  PS4 and Nextbox will be at least $450.  Quickplay iOS apps will become popular on WiiU and it will capture some of the would-be tablet market. Lifetime sales: 100++ million.

In the bad scenario PS4 and X720 will be $299, Nintendo will release Mario Rainy Day instead of Mario Universe, WiiFitU totally bombs, no apps are ported to the Gamepad, and Watch_Dogs is the last AAA 3rd party game we see.  Lifetime sales: 30 million.

In the realistic world I think the sales range for Wii U is 50-100 million since I think the core Nintendo titles will do well.  I also think the Wii U will be significantly less expensive than other systems... at least $100.  The Nintendo brand is still very significant as well, with last week Wii +Wii U sales exceeding the total for X360.  That means a significant portion of console gamers are buying Nintendo products, even at a point where most of us would say this is a low point for Nintendo.  When you factor in portables, Nintendo has about 50% of the hardware market.  Consumers like the brand, and will most likely buy its product.

For the time being I'm going to say 100 million lifetime for Wii U.  I'm assuming strong 1st party titles, moderately high pricing for competitors, the porting of iOS apps for gamepad, moderate 3rd party support from Ubisoft, Activision, Capcom and others, and some carry-over brand value from Wii as evidenced by the high end-gen sales of Just Dance, Wii Sports and others.  I might cut this prediction by as much as 50% after e3 or whenever we know more about future product and pricing throughout the industry, but for now it's where I optimistically see it.

The Wii U "price advantage" is killed by the PS3/360 which will continue to get third party support for the next 3-4 years. If devs can bother to make a Wii U game, they'll make a PS3/360 version too. Not going to ignore 150+ million users for a piddly Wii U userbase.

Wii U's not even competing with PS4/720 so I don't even see that as an actual problem. I dare ya (seriously double dare ya) to go into any retailer and try to talk someone getting a PS4/720 this fall into getting a Wii U. You're wasting your breath. This is a completely different audience, Nintendo lost a lot of this crowd a long time ago. 

PS3/360 are the bigger problem for Nintendo, I can see a lot of parents and even kids preferring those systems. They have far more games, cheaper entry price, better online services, better hardware bundles, and waves of $20 games. You can get a PS3 + 4-5 pretty damn good discounted games for $350 pretty easily right now, makes the Nintendo Land bundle look like crap. 

I suspect price cuts for the PS3/360 are incoming this summer/fall also. Both overdue.

A $199.99 PS3/360 with a game bundled this fall is a bigger problem for Nintendo.

Nintendo needs to get off their asses and make something NEW (NOT MARIO or a mini-game collection) that can break through and requires a new audience to get the system, something that's a big hit. Every other route is a dead end IMO. 

There still will be a market for the cheaper console for kids entering the game industry. I don't think young kids really care so much about the age of the console anyway, just as long as it has new games on it. 

The PS3/360 have Skylanders. And about 100 different LEGO games. And will likely have basically any Wii U third party game. 

Sony/MS probably honestly still have one more hardware refresh they could do with the PS3/360 (another die shrink + casing redesign) to be honest. Neither one has even gotten to under $199.99 which is kinda crazy to think about, because the majority of PS2 sales came after it hit $199.99. 

The PS3/360 is a problem for the Wii U for at least the next 2-3 years IMO, which is more than enough to kill any momenteum Nintendo is trying to gain during the formative years of the Wii U. 

If I'm Sony/MS I'd continue to support the PS3/360 with a couple of new games every year too, just to keep Nintendo's feet to the fire. There's also expanding markets like China, India, South America, etc. and seeing how the PS2 sold for years on end, I think MS/Sony both are viewing the PS3/360 "grey years" in a completely different light. 

Nintendo never, ever, ever should've made a system that was basically just a PS3-360, they walked right into a giant pile of quicksand IMO. 

JohnLucas, you're back?

Well, I think Vita will on average do a bit better than 4 million, so 5 million per year on average. WiiU will do even a bit better with good holiday-sales and Nintendo having some more cards to play than Sony for Vita. So six million per year on average.

Both I expect to last around 7 years, that makes:
PS Vita: 35 million
WiiU: 42 million

I don't think that will happen.

Animal Crossing New Leaf & Pokémon X/Y will outpace that easily in pre-orders while PS3 & 360 get 80 million life time sales a system.