For me, it is a bad idea to move to 2.4 ghz wavebirds.
-For one, there is plenty of range already with the 900 mhz ones. I have experienced less problems with 900 mhz phones than with 2.4 ghz ones at my work.
-2nd, microwaves run at 2.4 ghz, that can mess with the signal more than they possibly already do.
-Third, moving to the higher frequency will actually decrease the range that the wavebirds will reach. Just beacuse it is running on a higher frequency does not mean it will go farther. Check my microwave situation. Microwaves don't go any farther than the outer casing of the microwave itself. This is because the frequency is just not a strong enough wave length to go through solid objects as well.
-4th, they can interfere with home wireles networks. The average wireless networks for computing runs at the same 2.4 ghz.
The only reason I can see Nintendo doing this is to save costs, but they have to look at the functionality too. If more issues arise when it changes over, would they even think about going back to the original format?