It seems to me that there are times and places where a wireless keyboard and mouse is not appropriate, and that there may be a time and a place where they are. Do you have any policies relating to the use of wireless input devices (and if not, insights or opinions)?
My personal opinion is, "Please let me plug the stupid thing in. I know it'll work that way. With RF interference and dead batteries, wireless isn't worth the hassle." It just seems that with wireless dongles, bluetooth devices, and wireless USB coming, that it is becoming easier to find a wireless device than a wired one, and that this will be more and more of an issue. [My suspicion is there are higher profit margins on wireless devices, and thus companies would rather sell them.] Some of them include a battery charger, which is nice, but I suspect there is a large class of users who would neglect to charge it.
Wireless is inappropriate in a computer lab -- I shudder at the thought of the time that would be wasted to ensure that the batteries were charged, and, as for interference, well, I heard of a meeting where each of the dozen participants had a bluetooth mouse and wondered why they didn't work. Wireless doesn't make much sense for a server, either. I'd hate to come to my KVM and find out that I couldn't use it.
Wireless may be appropriate for a secretary -- for someone removed from other people who does a lot of typing. And yet, I have a hard time seeing why you'd need a wireless keyboard and mouse combo if you are sitting at a desk all day.
One place where it is appropriate is when a presenter has a computer across the room and is projecting onto the screen.