As well as Nintendo have done during this generation in terms of sales, it's clear that their strategy isn't one that is going to last forever. Some of the new people that Nintendo has introduced to gaming will move onto tablets and smartphones, whereas others will enjoy gaming so much that they'll want to progress onto more challenging games. 

The future success of Nintendo greatly lies in them being able to secure a new fanbase from the younger audience (10-13) in order to secure a purchase from them in the coming generations. Some of the fans that they gained from the NES/SNES era are starting to turn away from Nintendo consoles in favour of the competition (as is expected), but this would normally be countered by the gain of a new fanbase from the younger market.

It's possible that the increased popularity of "hardcore" games such as Call of Duty (partly due to 3rd party propaganda, and from the growth of Youtube channels such as Machinima) have taken this market instead. In the past it was always about Mario or Zelda, but times are changing - there is a strong anti-Nintendo mentality among many younger gamers that there simply wasn't in the past. Are the popular Nintendo franchises finally going to step aside to make room for a new round of mega-franchises?

TL;DR: "Hardcore" 3rd party games are taking the market that Nintendo used to secure in the past. This could have a devastating impact on their hardware sales in the future.

Maybe, if the world indeed ends in 2012.

The first two statements about Nintendo losing fans and strong anti-Nintendo mentality among some youth is nothing new.  I've heard it plenty of times during past few decades.  Also, a decent amount of those fans from NES/SNES did turn away from Nintendo already during the PS1/PS2 days.  However, a lot of them returned for the Wii. 

I don't believe in your last statement about 3rd party games taking the market from Nintendo.  Where is there proof?  I can link Nintendo's top selling games on the Wii and most third party games don't even come close in sales.  If anything it is the third party companies that complain they can't compete with Nintendo on their consoles.  CoD titles only come close if you combine the sales on multiple platforms. 

But there was always respect for who Nintendo were and what they'd done for the insustry - nowdays, Nintendo = Casual, and there's nothing Nintendo can do to change that now. 

There isn't any proof because it hasn't happened yet - I'm suggesting that WiiU is going to suffer greatly because they're aiming to please a market that doesn't care for Nintendo any more. If they lose the family market for phones/tablets, and lose the "hardcore" gamers to the competition; who have they got left?

Thought Rol when I saw the thread title (certainly would've been funnier -_-)

I think Nintendo's small size (in context) is going to hinder it in coming years.

Nintendo may never be, but they may be. No-one can accurately comment or predict whether Nintendo will or will not dominate the videogame market again. Only Nintendo through their own action or inaction can determine that. If Nintendo has the games people will come. Besides Nintendo doesn't have to do videogames, they haven't always been a videogame company. Nintendo could become a car manufacturer in twenty years time, heck they could go back to the Love Hotel business they experimented with (a Nintendo themed Love Hotel - it has potential, think of Samus).

It is fair at least to assert that the appeal of M-rated games is leaching younger and younger

WTH are you talking about?? They are already changing that, did you not see the 3rd party lineup for 3DS and Wii ?, they are already trying to rectify this.  Ninty never made these "hardcore" games anyway, sure they had GE and PD but that left with Rare. The only reason why no one has complained before is because 3rd parties were putting games on Ninty consoles that didnt suck. GTA, Bioshock, Tekken, MK, Mvs.C, SF, FF, RDR, Portal2, SC, AC these are million selling franchises that have made no appearance on Wii or have been poorly represented (looking at you Soul calibur and Final Fantasy), what are people supposed to think??

I think Nintendo did lose some of their fanbase this generation. I know I lost my confidence in them somewhat, although I still think their first party games are top notch.