Many moons ago I did a presentation on the futures of user interfaces where I talk about why true immersive 3D environments (not like LookingGlass but true 3D) were unlikely to be useful for standard corporate users and why voice as a command mechanism is a bad idea. I had a slide back then with a cartoon on it, that unfortunately I cannot now find.
Basically the scenario is this, you fire someone, they are upset. All of your systems can be operated via voice commands... so what happens...
Yup the person runs down the corridor formatting all the hard drives that they can. Now back then I worked in a unix shop so the command was "rm -rf /" but I think format c: works just as well. My point was that voice commands are quite inefficient for lots of users and are also subject to office noise interference, the example was just a silly way to show what I meant when I talked about people wandering up to your desk and asking "did I send the email to you?" and the computer sending the email you hadn't finished.
Now it seems that Windows Vista might have made the silly a reality.
Welcome to Firing 2.0, like Firing 1.0 but with sound effects.
(with apologies to the excellent XKCD)