A reporter from Inside Mac Games pointed us to an article about the official release date for Oni from the Gathering Of Developers. That date is January 29.
From IMG's story:
As we suspected, it appears that the PC and Mac versions will be held from release until the Playstation 2 port of the game is complete. It has been a very, very long time coming, but it finally looks like the long delayed Oni will finally see the light of day early next year. Stay tuned to IMG for more info on this game of hand-to-hand combat and gunplay.
It appears that the PC and Mac versions are a little bit ahead of that on the PS2, and so the release will be held until all three are ready to ship. Well, at least it's only a couple of weeks. :-)