Hello,

I just hacked Matrox' PowerDesk utility that comes with their XFree86 driver to work under NetBSD - I replaced all the direct I/O operations with calls to libpci. 
Whoever is intrested may download the tarball from http://macallan.homeunix.org/stuff/mgapdesk_netbsd.tar.gz
It works fine on my hardware ( G450 ), should run on NetBSD 1.6 or newer. 

have fun
Michael