Valve is showing Mac users some love by finally releasing Steam on the Mac platform. Add to that they they get a free copy of Portal with the download, but it's not just them, Portal is apparentlly free to everyon for the next little bit, so if you haven't played the outstanding puzzler/shooter I, and everyone else that has, recommend you check it out.
The nice part about this is that traditionally, despite how powerful the Mac is, it's not a gaming machine. The offerings available on the Mac are usually slim, save for some of the largest titles (World of Warcraft and The Sims, etc). While Mac gamers won't' have access to the full Steam library unless they run boot camp or something, it's a nice lob in the direction of universal gaming.
In other new that some people may feel is more Mac related though, Adobe has announced CS5.
This isn't news per se, but it does make everything you had before seem to be a bit duller. Or you can be like some of us and just keep on using the version you had before until you get the money for the upgrade!