Ryan's update was very brief and all he basically said is that Unreal Tournament 3 for Linux and Mac OS X is still being developed. Ryan claims what is going on is just "optimizing and fixing annoying bugs at the moment." It has been 479 days now since the Windows client first shipped... With this optimizing and bug-fixing work, I certainly hope that the UT3 Linux client ships with very few bugs and can run graciously with both ATI and NVIDIA graphics (though at last check, Ryan went without ATI Linux testing). There still is no release date planned for the Unreal Tournament 3 Linux client.
Ryan's mailing list message can be read here. In this forum thread are already over 140 comments by outraged Linux gamers.