Well, I don't agree that TP will do that to the Rev. First, no one would only buy a Revolution only for Zelda. No matter what functions Nintendo adds in, it's still a Cube game, and it can be played in its entirety with a GameCube. Therefore, whoever just wants Zelda is much more likely to buy a vastly cheaper GameCube than a Revolution. The NRC functions are great and all, but those alone won't persuade someone to drop money on a Rev by themselves; if someone buys a Revolution they will most likely buy other games as well.
Also, this won't be an issue if there are some quality games available at launch for the Rev. If we get a game that truly demonstrates the functions of the controller in a grand fashion (like SM64), then people will buy that game regardless. And MP3 and SSBR will probably be around sometime during the launch period; those games won't be affected as well since they are more than likely going to sell anyway. I worry about third parties, though, since their games can't be sparkling innovationy and shallow. Well, there can be a few of those which aren't expected to sell much anyway, but I hope the other third party offerings sell well too, since 3rd party tie in ratio is something that developers take notice of as much as anything.. But I'm convinced that if a 3rd party actually puts some efforts into Rev games, they will sell for what they're worth.
As well, Nintendo systems usually have a great tie-in ratio at launch. Zelda will only be a minor dent in this. Sure, it won't show up as a Rev game, so the tie-in ratio will be a bit less, but it won't drastically change how many copies of launch games are sold. Early adopters WILL buy more games, so there's little to worry there. And while it may cause a slightly lower ratio, it's selling hardware! Userbase is always extremely important, and Zelda will help spur Rev sales, which will only encourage 3rd parties to develop more for the Rev.
Any game Nintendo can get is all too welcome for the Rev launch. I'm not saying that Nintendo should have a weaker launch just because Zelda is there, but having it can only help. It will sell systems and not really affect the tie in ratio.
-------
Having said all of that, I agree with pretty much every thing else you had to say, Mario. I don't doubt this is a good business decision for now, but I'm very angry at Nintendo for doing it, and it may come back to haunt them in the future.
They would be essentially delaying the game to add in features that you can't even use unless you buy a Rev, which many Cube owners will not. So the GameCube owners will get cheated, since first they have to wait longer for a game when the system hasn't had meaningful support for a long time, but ALSO they won't even be able to use the features that caused the delay..
Twilight Princess won't take full advantage of everything the Rev has to offer, and therefore it won't be the complete and polished Rev game that I want. The true Zelda Revolution will push the controls and the Rev hardware, not only for graphics but to do things that the GameCube hardware just isn't able to (like how Pikmin couldn't be done on the N64). And at the very beginning of the development of this Zelda, Nintendo will be thinking about the Rev controls all the way, unlike TP.
I may be too sentimental, though..