...going to bring Half Life to Mac OS (not OS X).
Long story short, believe it when it happens.
I'd like to think it will, but Valve have form on this business of promising stuff and not delivering it.
Further, I wonder how much 'porting' will be done and whether they'll just do like Corel did with WordPerfect and like EA do with their Mac games, and (as I mentioned above) just kludge their PC executables onto Linux with Wine.