I mean.. there are some games (such as time crisis, where movement isnt such a key factor) that i could see the wiimote lending itself to being better than a mouse.
thing is... time crisis is an arcade and console game =p, but really a pc game.
i do agree though.. there are definitely certain games that lend itself to a wiimote. this video displays rez being played with a wiimote, and i think that would totally complement the gameplay on a whole new level.
as far as FPS's go though, and generally any other game where precise movements and reaction speed can determine the difference between life or death, i just dont see it being as effective as a mouse and keyboard.
and imagine anyone circle strafing around you! it was stated that large turns are generally a pain in the ass to do.. but how bout doing it constantly while shooting, and just... LIVING in general? just sounds like too much hassle for my worth.