After my last entry, I noticed that Linux, OpenBSD and hps' new stack all have ZyDas drivers, at least for the ZD1211 and ZD1211B. hps' zyd driver appears to be a relatively recent port to his new stack.
I have the OpenBSD one builing on FreeBSD's current USB stack. I still need it for other reasons, and a MFC of HPS' stack will never happen, so if we want to support it in 6.x, we'll need one for the old stack.
I get to the part where the driver tires to setup the MAC with the RF specific register values when I get a panic. I've not had the time to debug it further, but hope to find that time soon.
My experiences with BSDcan showed that I needed both USB and CardBus wireless working...