I wrote Elbox about the very same question. The reply was that if I could find a wireless networking card with the supported chipset, then it should work.
He said that using a USB wireless netcard wasn't recommendable; but I quite don't knwo why.
I'm going through the same problem here, and I think I will just hook up an accesspoint instead.
Let me know if you find a wireless networking card for use in Mediator.
