It is already. It's selling more than 12 Million a year. I wish I could say the same about PS Vita

http://media.tumblr.com/tumblr_m3u7sdCwXa1qc66wy.gif" border="0">

I really do think that now that there is a 2ds that the 3ds family of consoles will sell more than the ds. They will only get cheaper, and the 3ds has had a whole lot better of games than the ds ever had (at least to me). Parents will get on board even more than they are now (especially with the 2ds and with decreasing prices). I think the 3ds could be the best selling console of all time when it's all said and done, unless Nintendo decides to make the next handheld prematurely (many think the Wii would still be selling a ton if the Wii U wasn't out).

3DS: 102 million
Wii U: 32 million

It really depends on how long they support each system. If they support the WiiU till the end of the normal generation cycle it should be about:

WiiU: 40M-50M
3DS: 110M-130M

Hard to say, but I'll make a guess.

Wii U: 18-25 million

3DS: 80-90 million

I'll take the average and say somewhere around 21.5 million Wii U's and 85 million 3DS.

The Wii U was poorly designed and hasted out the gate to counter the incredible and sudden decline of the Wii, it lacks basic appeal, at least that's my theory. Seeing the tiny effects of software and price cut, and the short time window of effect on both accounts, this is looking more and more likely, Q1 and Q2 2014 will be conclusive though, even if it manages a decent holiday, that doesn't mean much, it had a very good holiday season last year and we saw what difference that made for the remainder of the year. Squeezed between the 7th and the 8th gen, it will probably be slaughtered on all points, from profitability, software sales, support and hardware sales from one competitor or another and it will likely be replaced a lot sooner than the Wii was.

The 3DS will fall victim to a collapse in the dedicated handheld market due to tablets/phones devouring marketshare and stealing the entire casual base (this has all but happened already) and the more core gamer will get their fill with home consoles, mirroring on smart devices and more core games arriving for the tablets and phones as the market expands and attracts more serious customers. We're already seeing this development in Europe and Japan, digital distribution will also contribute to this in the long run.
The DS had three consecutive years of over or around 30 million (!!!) consoles sold, the 3DS will never get anywhere near this and has a probable peak around PS3/360 levels right now and is set to track about 12 million below the DS after three years on the market now in february despite initially tracking above, launches aligned, this is is very similar to Wii behavior, only a lot sooner and in spite of reduced price and good support.

around N64 levels for the WiiU if all is said and done. (20-30 million)

around GBA levels for the 3DS (80-100 mill.)

WiiU, 80 million cause why not, its still too early to label it a failure cause the other two consoles might have the same problem after all the fanboy hype goes down

3ds 125 million cause it has no competition and the games are too damn good

3ds 120 million if they keep the games coming
Wii u 35-45 million i hope

Wii U atleast 50 million
3DS atleast 90 million.

I said in a thread before the Wii U will manage 49 million, but that is becoming increasingly more unlikely. I am leaning more towards 20 million consoles now before all is said and done.

3DS will do much better between 100-120 million in the end, I do not think phones will replace the handheld market anytime soon, but certainty put a dent into it.