It's kind of pathetic that so many people think the Wii is doing well. That couldn't be further from the truth at the moment.

Before I'd begin, I'd like to say I don't hate the Wii; I simply recognize it's imminent failure.  I think it's had a few good games, but I don't know if they've justified my purschase of the system.  With that said, let's begin.

Let's look at our first piece of evidence: loss of market share.

According to this thread, the Wii was at 48.9% marketshare!  It's now at 48.7%!  While you may point out that this is a relatively small change, I'd like to remind you that exponential functions start off increasing slowly before they shoot up.  This is clearly the case here, and we'll be seeing larger and larger loss in market share before this year is over.

More importantly, this doesn't even take into consideration that the X360 is being undertracked by 1.4mil.  With this taken into consideration, the Wii's market loss becomes even more disturbing.

Exactly how long this loss of marketshare will continue is hard to say at the moment.  If you look at all the amazing releases on the PS3 and X360 this year (Mass Effect 2, God of War 3, Gran Turismo 5, etc.) things start to look bad, especially when you consider all "core" titles being released by Nintendo are simply rehashes of the same old thing (How many times do I need to save a princess?) from ancient franchises.  It's entirely possible that Nintendo could give up first place in the console race.

Whether you want to recognize the Wii's impending doom or not, other, more important people have.  Best Buy and Target won't be buying anymore casual titles for the Wii.  How much of the Wii's library is that?  Here's some research I did:

If you look at thisrandomly selected page from the Wii's library.  9/10 games are casual.  If we extrapolate a bit, we can estimate that somewhere between 85 and 95% of of Wii games are casual.  Best Buy and Target are reducing Wii shelf space by 85 to 95%!

I think the real issue is something people have long dismissed.  The whole "Wii is a fad" argument was pretty much dropped as it continued to sell well for several years.  However, I propose to you a radical new idea:

First, the Wii's novel motion control was a fad that created interest for the first few years.  Then, the balance board and various excercising "games" that came with it were a second fad that created an obsession with the Wii entirely different from that of the first few years.  Yes, much like how the Wii's power was compared to that of two Gamecubes ducktaped together, interest in the Wii has been maintained by two fads linked one after the other.

Interestingly, that fad seems to be ending.  Wii Fit sales have sunk to a pathetic 19,514.  How the mighty have fallen, indeed.

To conclude, we've seen various indicators of the approaching storm for the Wii.  I think we're about to see the Wii go from dominating to a depressing second place.  Hell, if both HD consoles continue to sell as well as they do, we might even see it in third.  For a console that showed such potential, it will be a truly depressing end.