There are two things, IMO, that make it unlikely that the Wii will maintain market dominance. 1) The controller is flaky. I'm sorry, but it is. Let's talk about something simple. Go into the Wii menu, point the controller at the screen and then rotate it as though you want the finger to be pointing down, instead of up. Watch how jittery your cursor becomes. For more important examples simply look at EVERY SINGLE GAME that uses the accelerometer, rather than exclusively relying on the pointer. If the game calls for very broad gestures, like Wii Sports Bowling or baseball, it's fine because the gestures required are so broad and linear. But how about the putting game in Wii Sports Golf, or everything about Wii Sports Boxing? Terrible. Not even acceptable. These problems apply across the board. Even Nintendo's flagship title, Time Princess, suffers from it. How many times have you tried to initiate the shield attack with the nun-chuck and had Link perform a spinning sword attack instead? How many times have you tried to do a spinning sword attack and had Link do nothing instead? This kind of thing simply doesn't happen with buttons. It's one thing with a game like Street Fighter where you may try to perform some move and it doesn't work, but in that case it didn't work because you failed to do it correctly. As long as you make the correct motions, your on-screen character will perform EVERY time. This is not the case with the Wii. The controller is a brilliant idea, but it's not where it needs to be yet.
And 2) the system is WAY underpowered. The graphics are comparable with the original Xbox, and the sound can't even be compared with that. The sound is more along the lines of the Nintendo 64 or PSX. It's easy to say, "Sure, the graphics aren't as good as the 360 or PS3, but they're good enough." And they are. They are good enough. Right now. But "good enough" is not a static term. There was a time when NES's graphics were more than "good enough", but that doesn't mean a system released today that was not capable of more would continue to enjoy that status. The Wii's graphical capabilities are about five years old right now -- meaning they are on par with what could be produced on game consoles five years ago. That's not terrible, especially considering what they bring to the table in terms of a brand new way to interface with the games. But look four or five years down the road, when all three of these systems have mass market prices. The Wii's graphics are going to be 10 years old!. It's sound capabilities only on par with 15 year old systems. This will become a progressively bigger problem for Nintendo as time goes on and developers make better and better use of the 360 and PS3's complicated multi-core architecture. It will be interesting to see how Nintendo deals with it.
Finally, online is an area that, for whatever reason, Nintendo just can't grok. How they could get it SOOO terribly wrong after MS has been showing them throughout the original Xbox's lifespan how it's done is completely beyond me. I don't list this as one of the two reasons that Nintendo won't maintain its lead, because if this were the only problem, I don't think it would be enough by itself to hold them back. But it is a pretty damned big misstep and sooner or later they're going to have to learn what online gaming means, at least for Americans, if they want to remain successful.
The first paragraph is unwarrented. Maybe it's where you have your wii, but I can do what you said about the pointer just fine. The sensor bar is much more sensitive to light than nintendo wants admit. You should be playing your wii in a dark room with the curtains closed or in a room with diffused light sources. Even accepting the fact that you are having issues and that a lot of other people are, my question to you is why would you want to browse with the wiimote up-side down? Nobody would do that, and considering this I doubt nintendo added the complex math to the code of the wii interface to do this. So it's really a bad example as you are trying to make the program do something it wasn't designed to do.
The motion gesture issues are only issues because of the fact that all of your examples are first-gen games. The upcoming Metroid Prime 3 basically uses motion gestures exclusively, rarely relying on button presses for anything but shooting and jumping. Opening doors, pulling levers, ect.. all done with gestures. Taking this into account and the fact that all the early reviews seem to comment on how immersive the controls are, I'd say the acclerometer issues are fixed. The real issue with this one is that third parties are releasing poor games for the wii and/or haven't figured out how to code for the wiimote properly. I have no doubt this won't be an issue people are talking about this time next year.
Yes the wii is waay under-powered. Unfortunately for the gamer though, m$ and sony aren't doing anything with all the extra hp they have. The xbox has been out over two years and it's had basically one stellar game released (GOW) and oh gosh, suprise, it's a fps! Exciting environments, nah, just your typical muddy, generic , ww2 style battle-zones. Sony doesn't have anything at all. Bioshock is pretty, very pretty, but it just seems like a bad-rip-off of the old Hexxen titles to me. Characters that shoot "magic" (in this case mutations) are nothing new. I will admit that it looks amazing though, it just doesn't exactly play amazing, probably because, yet again, it's just another shiny fps. they will both sell well though and that is the important thing. The thing is though, as well as they sell, they can't top the sales charts of the wii games in the long-run.
Now you go look at the wii side. While there aren't a lot of really games that I would like to play, there are a lot of games that are selling amazingly well. I HATE mario party, for example, but it is consistently at the top of the charts. The casual gamer market is taking over (unfortunately for us) and they are buying up games we would consider crap like hot-cakes. The casual gamer isn't going to want to buy a new system, if history shows anything they'll stick to what they've got until the system is literally dead and nobody releases any games anymore. What the casual gamer has, is a wii. If they don't have a wii, then their friend does, so when it's time to get a console, that is what they'll get.
With that being said, there are a lot of good titles on the wii right now, arguably more than the 360 and this fall marks the release of a lot of key titles for the wii. The 360's fall lineup is impressive as well, but one of the two main block-busters is guitar hero III, which will also be on the wii. On the other hand, the wii has metroid prime 3, mario galaxy, and super smash bros. If you like those games or not, the fact is, they sell well. The sell well enough to be console sellers. And I see no signs of this trend stopping in the future. Nintendo will churn out it's IPs consistently over the life of the console and people will buy them, and the console. Also the wii seems to be a great experiment on Nintendo's part, and they'll be releasing various controller gimmicks in the future and like them or not, a lot of people will buy them. M$'s only crazy game seller, the one people will buy a console over, has been Halo. Once Halo is released, nobody will have anything to look forward to (as it takes a loong time to make the next halo).
I totally agree with the online thing. They screwed up, and in the long run it might come back to bite them. On the other hand, m$ really only makes money off of online purchases, just like nintendo, and while the vc game sales have slumped, they are still selling well. Since a lot of the VC titles are owned outright by nintendo, unlike m$ their sales are essentially pure profit. Of course this hurts the consumer, but my point is I think they haven't utilized the online aspect much because they haven't had to. Once the wii gets in a bit of a slump (and I DO imagine that will eventually happen, for a while at least) nintendo will step up the online aspect and hopefully, except for the retarded friend codes, all will be well.
And in closing I just need to point one thing out. It has been almost a year and the Wii is STILL in short supply. Think back through the entire history of video games, do you ever remember a console that has done that? That should tell you something of it's longevity. We can't talk about wii sales slowing down in the future until there are actually enough wiis to meet the current demand. At this rate it'll be this time next year before every person currently wanting a wii has one.