Hi CDS,
No, I was thinking more of a PC (Server) to Camera (Client) USB cable that just happens to have a wireless link in the middle of the cable so to speak.
The USB model would still stand only that the two wireless ends of the "cable" would have to pass USB signals properly. It would then still work.
I.e.
USB WiFi USB
PC-------------| - - - - - - - |-----------Camera
A A
Where A is the device to transmit/receive USB signals via WiFi. Basically a peer-to-peer WiFi network. Each A box would need to be powered though, or maybe just the one on the camera side of the link.
There is a device that allows you to run a USB device on the end of 100 foot of CAT 5 so someone must be working on the wireless bridge system, probably for things like USB webcams etc.
Of course, at the moment a long USB cable will do.

Cheers
Ian