..Or better said, I believe it's ridiculous for a device like a laptop needing to have two or three 2.4GHz
radios just because somewhere at firmware level, protocols are not compatible. New chipsets do
wireless display (WiDi) using the the wifi radio, so why not mice and keyboards.
I agree that it's ridiculous for a laptop to have so many radios. Something needs to be done here.
Bluetooth was supposed to provide most of the PAN (Personal Area Network) connectivity, and WiFi the WAN (Wide Area Network) connectivity but I think bluetooth failed miserably to deliver. Bluetooth mice and keyboards continued to disappoint me and almost everyone I talked to about it. These days if I go wireless, it's going to be a non-bluetooth mouse and keyboard, and that usually means Logitech for me. Now, it seems that the manufacturers agree that one radio is easier to manage, so they are starting to put everything on WiFi, but it's just too heavyweight. Unfortunately, I concede that it's also proven to work, and works well.
I use a 2.4 GHZ wireless mouse made or marketed by hama, that uses two AAA in parallel. The batteries last about 7 months and I never turn the mouse off , so battery life need not be a concern.
The problem is not with the 2.5GHz, but the use of a very complex protocol like 802.whatever. For a mouse all it needs to do is send very short packets fairly infrequently, but I would expect wifi to require significantly more overhead as it is designed for much higher payload sizes, plus all the security stuff.
I am not deeply familiar with the WiFi protocols over the air, but perhaps in the future there will be a light wifi, or something that just just uses the bottom-most communications layer for light traffic like mouse and keyboards and other devices (like bluetooth, but actually works) and perhaps there can even be a service class, that uses less power from the laptop radio to transmit these bottom layer lighter protocols. Then you only have one radio in the laptop, the protocol is WiFi at the top layer, but just a packet layer at the bottom, and the transmitter can adjust its output power for different classes of peripheral.
Giving your mouse, keyboard, and display an IP address and using TCP/IP, a fully routable protocol, is still pretty ridiculous. Soon they will amend that to include a harddisk, currently the realm of wireless USB. I know, it's just a 32-bit number, and it's basically local, and probably given from the auto pool 169.254.0.0/16 , but still.... I can't get over it. Perhaps that's because I grew up on the Internet, long before household NAT gateways and firewalls, and when my desktop Sun or Apollo workstation was directly connected to the Internet through our router.