An interesting pattern I have seen is that people act completely irrationally when it comes to stocks which is why their investments do so poorly ...

When Apple was approaching $700 people argued with me that it was going to fall in value because Apple was the largest tech company in the world, there market share was about as large as it could be, and they were on a multi-year winning streak; essentially, since Apple was about as big as it could be they would justify an increase in the stock price through some unknown avenue of growth.

In contrast, Nintendo today is being dragged down by hardware losses they took on the 3DS that (probably) will soon be done with, expenses they've taken to launch the Wii U which will (probably) soon be over, and because their sales were simply not unbelieveable; and people are arguing that their stock will continue to fall because there is no way that the next few years will justify an increase in the stock price.

I don't know where the bottom is for Nintendo, and the stock could potentially fall below $10 in the short term, but in 2 years they will likely be turning a profit off of every 3DS and Wii U system sold and selling 100+ Million units of software a year and brining in between $1 and $2 billion in profit a year; and if Sony or Microsoft screw up, or Nintendo releases a popular add-on, Nintendo could be on track to repeating as the leading console of the generation and surpassing the Wii in lifetime hardware and software sales.

Thing is, I can't see the Wii U being dominant whatsoever in the next few years, or even ever. We've yet to see it demonstate anything that puts it a generation ahead of the existing consoles and therefore gamers and customers will not want it as it offers nothing worth the asking price. If MS simply release a more powerful xbox that can kick out a much prettier CoD, that will crush the Wii U. Don't get me wrong, I hate CoD, but that crowd is a very dominant one in terms of marketing. 
Sony and MS would have to essentially release piss poor consoles, and on top of that, the steam box would have to be dire, for the Wii U to be a market leader. I just can't see that happening. 

People said exactly the same things about the Nintendo DS, 3DS and Wii ...

Nintendo is not run by morons, they have a fairly good picture of what Sony, Microsoft, and Valve can do and they felt confident with their approach with the Wii U. In my opinion, the likely reason for this is that the cost of producing a system that is significantly more powerful than the Wii U is too expensive to make a viable product and game development costs are too high to make these games profitable; and Nintendo is happy to let Sony and Microsoft product $500 or $600 systems with $70 to $80 games.

The Steambox will be interesting but I suspect it will be much more expensive up front that a typical game console because it will be manufactured by third parties who sell it for a profit; and a system that Microsoft would manufacture for $550 to sell for $400 will be sold as a Steam box for $700.

The 3DS had massive price issues to begin with...
The Wii however had the "cool gadget" factor going for it. Nowadays that belongs to smartphones and tablets. The people who bought the wii for that reason have it now as a dust gatherer and certainly aren't looking for an upgrade. The wii u does not appeal to the casual market that invested so heavily in the wii, nor to the gamer audience as it offers the same games and a few casual titles. On top of this there is the marketting issue that people are not clear what it is  - many think it's just a new pad rather then a new console. 
If Steambox doesn't run windows, and is a mini-itx format, it could very easily cost $550 and be damn powerful as well. The advantage they'd have is bulk buying components if they aren't using customised parts. 

Im very impressed. Its doing a great job outselling the PS4 and Next Xbox, which have sold a grand total of 0 consoles in 2012.

People bought the Wii to play local multiplayer games with family and friends, something that no one is really offering except for Nintendo ...

We know little about the Steambox yet, but the suggestion is that a company like Asus will manufacture it to sell the hardware at a profit; and, although the hardware will likely be powerful, I doubt it will be in the same price range as other consoles.

My point still stands though, Nintendo has an excellent idea of what Sony and Microsoft can produce and sell for less than $450 without going bankrupt and believes the Wii U is good enough to compete against them; and, while Nintendo could be wrong about what the market will support, I doubt Nintendo would be wrong about what Sony and Microsoft can produce. Nintendo probably is prepared to fight against consoles that are 2 to 4 times as powerful as the Wii U and come with their own advanced UI device.

People also bought the wii to keep their kids and bored wives quiet. It wasn't really ever a gamers console. If Asus use their own hardware rather then custom making boards as on the other consoles, that would keep prices down but yes, as of this point in time all we have to go on is speculation. 

The Wii U though has only shown us gaming power that is equivalent to the PS3 and 360, just at a lower power consumption. Do you really think that after 7 years MS can't release a noticably more powerful console that uses the same power as the 360? If they did that, they'd be playing with 100W more power which is a significant amount. 
Nintendo may be willing to fight against consoles that are more powerful then it, but it looks like developers aren't behind it, and they have good reason why not to be. Why develop for an awkward console when it does near enough the same job as two consoles that are easier to program for and have a combined user-base of 140 million? If the next xbox and ps4 come out around the same time, then devs will just move over to them and write off the 360/ps3/wii u as last-gen within about 2 years. 

Mazty, aren't you speculating just as investors themselves do?

Good for you. I got my stock almost at their low point, at 1.44€. Now it is at 2.95€ and by the looks of it, still climbing. That is how you make money. :)

I´ll say my opinion a few months from now.It´s still early.