OS X has no included way (that I can discern) to create a network bridge. And I seem to be the only one who wants to do this (I want to give qemu's emulated interface a direct connection to the LAN via a bridged tap device).
This is really, really pissing me off. I just hope that Darwin has the functionality and that it's only the userland tools that are missing - I may try compiling some of them from FreeBSD and see what happens.
I'm a little miffed by this. Even Windows XP includes network bridging these days... come on guys.