There is a difference between motion sensing and tilt sensing.
Wii = Motion Senseing, meaning it recognizes, pitch, aim, direction, etc.
Ps3 = Sixaxis. It recosizes six dimensions, up, down, left, right, up diagonals, and down diagonals.
Sony had the six axis in plan from the start and had it in developement before the announced it, and before the
wii had announced the
wii's motion sensing. Even then, the ps3 and the
wii have WAY different uses for the motion/tilt sense. And as other people have brought up before, the
wii wasn't the first to use tilt sensing, many games before had tilt sensing, the ps1 had it's gun which recognized left and right, the gameboy had kirby tilt and tumble, sos if anything, nintendo is using OLD light gun technology with some tilt sensing.
Sony has the sixaxis as a nice feature, most games allow you to turn it on and off, and some games don't have it at all. I never remember using it in call of duty 4 xD.
So there's Tetsuka's rant.