Complicating? It's mimmicking real life movement....which is what the Wii is all about.

About the control issues you have. Pull analog stick backwards, while walking, and you walk backwards. Turning you'd do like Metroid. Strafing by pulling sideways and the analog stick, while walking. Crouching would be done by...crouching. And lying down would be unlikely to be needed. I really don't see any problem at all.

And what if a guy in a wheelchair wants to do a walk-a-thon? he can't, that's why he is in a wheelchair. Some things you can't do after you end up in a wheelchair, which i why it's not something people wish for. But you know what? I don't think too many people in wheelchair would be playing an FPS on Wii anyway, so does it matter? not at all.

 The Wii userbase may not be into FPS as much as the PS3/360 users but your second point I think is irrelevant.  Sure keyboard+mouse will beat Wiimote but they also beat dual analog sticks and the console FPS market has thrived.  

As Stof said, what's holding back the Wii FPS is lackluster online support (no voice chat still) and the fact that the other consoles are putting out some extremely beautiful FPS like CoD4.  The graphics part can't be worked around as no Wii FPS will beat what the 360 and PS3 equivalent can look like on a technical level when comparing textures and whatnot, however that's where something like the head tracking demo is so important.  Sure the wiimote settings are already better than dual analog sticks for most people but if you incorporate something truly innovative and gamechanging like the head tracking demo or something similar and put it into a solid online game with voice chat it could set a new level for FPS immersion that can't just be ignored.  That is how the market for Wii FPS could explode.

Being one of the first to bring up processing power I think I may have to clarify the point ...

I don't actually believe that processing power really matters, in particular when it comes to graphics, but many of the best FPS developers have the complete opposite opinion (they think processing power mattes especially when it comes to graphics). In general, the FPS genre is focused on "Realistic" graphics and in many cases (FEAR) the focus on graphics is so extreme that they give up dynamic environments in favour of better lighting.

The developer I believe are well suited to the Wii's mindset is Free Radical being that their previous generation shooters were more focused on unique style than flashy effects:

I don't think the Wii will become the FPS powerhouse that it should. It's true that the Wii can hands down control better than the 360 with games like Metroid Prime 3: Corruption and Resident Evil 4: Wii *and* still be able to even fall on the Classic and Gamecube controllers for those people that don't like motion controls but sadly FPS games have *always* been about power.

FPS games always try to one up all other games by having the most realistic physics, the best real time lighting, the smartest AI, the flashiest weapon effects, ect, and for FPS games to really get popular on the Wii, the Wii would have to let developers one up each other. With games already out on the 360 the Wii could never touch power wise, developers would never be able to one up each other.

Uhm,  I am the OP.  And since I wrote the OP I know that my point was about the wii remote's use in FPS games.  The head-tracking technology was mostly an afterthought of "I would like it if they used this also".

On the subject of head-tracking in FPS I do think it can be utilized in a number of ways in FPS games.  Obviously it isn't going to work as the primary form of movement but using the analogue stick to move the character and letting head tracking determine lean would certainly work.  The real issue I think a number of people might run into is that utilizing head-tracking properly would likely require the player to be sitting in front of the screen, otherwise it might look strange if you were sitting to one side.

I think head-tracking has enormous potential in the FPS genre.  Just imagine its potential uses when used in conjunction with a cover system. 

 Pfft. "Watering down everything"? So Wii FPS's won't have a silly physics engine or bloom everywhere. That doesn't mean the Wii isn't capable of producing a fun, unique - and pretty - FPS.

You know what I think is really, really funny?

When people tell the OP what their thread is about. I think that's hilarious.

Anyways, like I said before, the Wii provides the absolutely greatest degree of immersion possible amongst any of the current-gen systems.

Given that the Wii2 will likely include improved Wiimote control + competitive graphics, I'd say that will be when Nintendo triumphs over the FPS market.

 Weeheehee, you just made my morning.  UT2k4 physics is pretty bad and considering the fact it just doesn't happen in anything but singleplayer, yes, yes it is very shabby.

Metriod Prime 3, while not technically an FPS, is still the first game of that type I've actually enjoyed. I never learned how to aim with a joystick and hopefully now I'll never have to. Also have MoHH2 to try out when I get around to it. I don't need the fancy graphics and head-tracking whatever fancy things you all are talking about, I just love the pointer, reminds me of when I used to play the first FPS's years ago on the PC.

 I actually agree with you quite a bit but I have to wonder if the one-ups-manship is limited only to graphics.  There are definitely other areas where the Wii FPS could try and one-up the 360 FPS but the question is would people respond to it or ignore it in favor of the traditional?

Without knowing what innovations they might come up with it is impossible to predict how well such things could compete.  But I have to ask if you think that going outside the paradigm of "raw power begits raw power" could work for them? Or do you think that they are stuck forever playing second best in the eyes of FPS faithful?

I don't think there is nearly enough info to predict what "will" happen, which is why I am focusing more on the possible outcomes.