You can probably run a current kernel and old userland; the HAL needs
updating in addition but it's part of the kernel.  Trying to backport
support from current to a 2.0 kernel is not likely to be a
satisfactory experience.

I am running a current kernel and userland with various ath(4)
devices, and it's at least mostly working.

-- 
        Greg Troxel <gdt@ir.bbn.com>