FYI… recent SVN revisions now contain much cleaner support for Mac OS X!
I recently got the opportunity to setup a Snow Leopard system for development which enabled me to fix all major / obvious pitfalls, mostly related to the build system. There’s at least one annoying Phonon-related issue left which causes a crash on exit (only for builds using PHONON=1, of course), but it can safely be ignored. Also, as it appears to be a Phonon bug, it may only be fixable by the (former) Trolls… to be honest, I’m not exactly sure about this…anyway, other than that, it just works (TM) ;).
Quick build instructions are here.