I don't think I could duplicate this reliably yet, but:

* NetBSD can be installed on an Intel Mac mini using Boot Camp.
* The wired ethernet seems to not come up correctly (says active, but no pings
  exchanged); it's msk0.
* The airport extreme just shows up as ath0, and works fine.

Haven't done video or anything yet, but once you can get a kernel loaded and a
source tree in place, the world's your oyster.

I am thinking that I will do a factory restore of OS X, then carefully
document the Boot Camp procedure and other facets of how to get the machine
up and running, without things like "maybe I can load Linux on this... no,
that just killed it".

-s