Hey, dont diss Nintendo just because they came up with something that's already in existance for another handheld (that isnt even very high-profile in the market, at least until the European launch) Nintendo dont have the reputation for being "copying b*s*a*d*" either, I mean it's the other way round in most cases. They made the first Light Gun. It was copied. They made the first shoulder-buttoned controller for more "advanced" gaming at it's time. It was copied. They revolutionized controlling movements in 3D games with the analogue control stick. It was copied. And so on.
I've always known Nintendo for being original not only with their games, but innovation for new hardware too. So they made a wireless link for the GBA, big deal. This will probably be the future for handheld multiplayer anyway, just like the wireless controllers are already handy for hectic multiplayer mayhem on the big console without fear of tangling up the controller wires for the umpteenth time.
All in all, it's not the end of the world just cuz they made something "new" for a handheld, it wont boost GBA sales sky-high, infact it probably wont even have much effect at all, so quit whining.