Quoth Colin Paul Adams on Boomtime, the 55th of The Aftermath:
This is not supported by the b43 device driver, so Linux on this
machine is not on.
That doesn't necessarily follow: I got wireless working on the
first-gen air with ndiswrapper; ndiswrapper is sub-optimal, but it
works in a pinch. I haven't been as lucky with the second-gen air,
though.