From the leaked Windows 8 plans, it seems that Microsoft is looking at a future with richer sensors on personal computers. I would love to see this happen. I'm a big fan of Apple's popularization of accelerometers in mobile devices, too. Interaction can be so much richer than just keyboard, mouse, monitor, and speakers. Ubiquitous cameras and microphones would be sweet, though creepy.
On that topic, someone in my research lab recently made a comment about how cool it would be to put accelerometers and gyros in mice. Potentially you could go without the light sensor entirely. See IMUs for more. The Wii remote is sort of like this. And accelerometer mice have been made before.
The counter argument (from someone else in my lab here) is that full accelerometers and gyros would be much more expensive than current mouse technology, especially for the same amount of reliability and precision. But accelerometers and IMUs aren't completely off the charts for price. Maybe you could go cheap and just augment normal mice with accelerometer only for now. (And the raw part is even much cheaper than the breakout boards.)
I mean, it would be sweet if you could pick up your mouse and wave it around for 3D control in certain apps and games, right?
Logitech, Microsoft, Apple, someone, please get this out there. Thanks in advance.