Gentoo goes OSX. I’ll have to install and see what this is like later. As long as it doesn’t take days to compile… (Gentoo gag #56)
Fink, which IIRC is Debian based, already runs Linux apps, although sometimes badly. This Gentoo packager brings emerge/portage, easy app pull and install from the CVS tree. Hopefully this may, and probably will, package Linux apps for OSX better than Fink.
OSX is a geek dream, you can run MacOS classic, Windows, Linux, UNIX and of course OSX apps all on one box – in a easy way.