What about games like GTA or Just Cause 2? With this you get all the advantages of a controller(triggers to control car speed, and variable turning) but you don't get the super bad aiming of the analog sticks. This would also be good for just planin ol messing around in games like NV and Oblivion, although like you said it is useless for people who only play competitive FPS games.
Yeah, I'm only saying that for me it's useless, being wireless I could give it some use (if it didn't cost so much), but as it is, it's absolutely useless. I
don't like hate GTA games and 3rd person games in general*. As for Oblivion and the likes, yeah I could use it for that, again to play from my couch, hence wireless is a must for me, and now that I think of it kb+m is just plainly better in RPGs too. i.e what do you do in menus? I don't see this device working extremely well when navigating the many menus in Oblivion.
I just don't see any benefit on these devices, maybe some day... but until they can trully replace the mouse and preferably both kb and mouse I don't think they are very useful. I believe in dedicated peripherals that fullfill their purpse, rather than generic ones that try to do everything and master none, so that's why I think that these motion-sensing controlers must be wireless at the very least. Also it would be nice if they had a built-in writing feature so you could write on the screen and it would recognize it and write it down. I'm not talking about software, because I know that already exists, I'm talking about a hardware/driver implementation so that you can use it in-game.
*I did like Mafia though and in that game I just used a wheel, which was 100 times better than the kb or a controler of any kind will ever be. Yeah it was not the most comfortable way to play afoot scenes, with a wheel in front of me but it worked and the overall feeling was much much better.