The numbers don't really seem to add up. Generally after a few years sales start declining. Although, the Wii U has been up YOY for the last couple, but it's still not by a huge amount. I think it has a chance as long as Nintendo keeps fully supporting it and keeps bringing great games, but if they stop it will sharply decline and won't reach it.

I truly believe that this is why the NX shouldn't be a new console.  The rinse and repeat formula for hasty console releases is only going to put Nintendo in the same position Sega was in the late 90's.  We've seen the trends, excluding the Wii, every subsequent console that Nintendo has released has sold worse.  All things equal, unless Nintendo has a brilliant idea for the NX like they did with the Wii (ie. catching lightning in the bottle) it's fair to expect the NX to sell worse than the Wii U (just think about that for a second!)

I was listening to yesterday's Nintendo Voice Chat on IGN when it occurred to me that there really isn't an easy path for Nintendo to put out a killer console and regain substantial market share.  The Fusion idea could be a hit but we are already seeing something similar with the Vita TV and that concept isn't selling well (because nobody wants a dedicated handheld anymore, even one that hooks up to your TV).  It also doesn't necessarily fix Nintendo's 3rd Party problem and there will still be software droughts (it just means that Nintendo will have 3 month software droughts on a unified platform instead of 6 month droughts on separate platforms).  Finally, the Fusion is a big risk for Nintendo because if it isn't popular then Nintendo won't have a handheld device to bail them out (like the 3DS is currently doing for the Wii U).

I also don't think that releasing a powerful console is the solution for Nintendo either.  First, I don't think Nintendo can compete in the technology world against Sony and Microsoft.  Furthermore, the Xbox One is not selling well as it is, so I don't think there is room for a third player to release a clone of the PS4/XOne at this point.

That said, I don't think that the future looks dark for Nintendo, at all.  The mobile world is a huge opportunity for them and I really think that the NX should be a new handheld platform that integrates the quality of life concept that Nintendo has been speaking about.  Dedicated handhelds are in trouble, but if you can integrate some quality of life concepts (maybe a heart monitor?) that aren't currently available on smartphones then you can give people a reason to buy it alongside their smartphone.

As for the Wii U, if Nintendo doesn't have a brilliant new idea for a console then why rush to replace it?  Nintendo has a very loyal 10 Million user install base on the Wii U right now.  Graphically, the Wii U is powerful enough to make the games that Nintendo wants to make (who wants a more realistic version of Mario Kart, anyways?)  I say that, for the time being, Nintendo should keep releasing Wii U games like Mario Maker and earning money from software sales.  They should cut costs on the Wii U by finding a way to use the 3DS screen as a replacement for the gamepad and sell a $100 Wii U.  Meanwhile Nintendo should slowly move its focus away from home consoles and into the mobile and quality of life world.  I'm not saying that Nintendo shouldn't keep its foot in the home console business, but I don't know why the Wii U needs to be replaced in the short-term in order for Nintendo to do that.

I expect 17.5M lifetime

It's really hard to reach 20 million, but not impossible, that's for sure.

I'd love to see Nintendo turn things around with Wii U but I feel as though they missed their window of opportunity. They went with a hard to develop for architecture, they didn't advertise well, they priced the system too high and failed to have a deep enough price cut when they dropped the price, they've been dragging their feet on improving their online, and their publisher relations have dropped like a rock. Naming the system Wii U was bad enough because by default people associated it with "Wii" but they messed up in so many other areas, it's baffling. Could they turn things around? Well we're already seeing better sales in North America but I doubt we'll ever see Xbox One level sales, much less Playstation 4. Heck, I doubt we'll even see the system reach 20 million before the NX comes out.

Yeah we know that and there is a reason about that!
The comparison is flawed,stop it,gamecube had a price cut of 50$  in 2002 and another one of 50$ in 2003 and the gap isn't growing as you say,they are doing similraly in the third year,gamecube sold 3.9m in it's third year... after 6.1m in it's first year and 5.7m in the second because of the price cuts...

This.  I couldn't say it any better.  Additionally, I don't see the Wii U below $200.  Nintendo is taking too long in slashing prices significantly.

there are like 10 Ninty systems between HHs and home consoles and only two of those were supported past the point where the successor was out. Now if you're a betting man it would be stupid to think that Ninty would support the Wii U longer than it has too cause history has shown MOST of the time they do not.

March npd had mario party 10 at 4...Anyway don't use the npd chart,Nintendo's games are exclusive,npd charts usually is full of multiplats,we need an individual chart,in order to have good picture....

the wiiU has sold 500K in the first three months, I don't see how that translates to 4 million this year. The wiiU is going to be dead after next year.

Last year Wii U sold in 13 week 501,000. +3,600,000 in 2014

This year Wii U sold in 12 week 507,000. +4,000,000 is very possible.