The official Westlake Interactive site has been updated with a status on the Mac version of Unreal, including word that there will not be any further updates released in the forseeable future (thanks Tim Tibbetts of 3DFiles). Here's the whole thing:

Unreal 224b7 is the current version of Unreal Mac, and will be the last update for the foreseeable future.

It has been a very difficult decision, but after over a year of providing free updates to the Mac community in an attempt to keep the Mac version of Unreal up to par with the rapidly changing PC version, we have to move on. During the past year we worked on Unreal updates in the spare time between other projects, outside of our normal contracts, but this has become increasingly difficult. Because of changes on the PC side, we have almost completely re-written Unreal Mac several times since the 1.0 release, even though we were contractually obligated only to fix Mac specific bugs. We thought each update would be the last, and would finally allow the game to be played to its fullest. But every time the Mac version caught up, another patch was released for the PC. And with version 224, the Mac version is now up to the last public version of the PC that it is possible to update to. We are aware some third party maps only work with the 225 PC version, but unfortunately we never received the 225 PC code, and the original PC developer no longer has it (after releasing the PC 225, the code was modified to a 226 version that was never cleaned up enough to be released).

Unreal Mac is still supported (as it always was) by MacSoft, and they are the technical support provider for anyone who has questions or problems with the game. Any email about Unreal sent to Westlake email addresses will only receive an automated response with this message and the contact information for MacSoft technical support.

Work continues on Unreal Tournament Mac, which is still scheduled to be released within a month of the PC version. We are doing extensive testing of Unreal Tournament to provide the most stable and fun experience possible when it ships. And with the cooperation of Epic(the original PC developer), we hope that Unreal Tournament Mac will require few if any updates after it ships.

We hope our decision to suspend maintenance on Unreal Mac and concentrate on bringing great new games to the Mac will be understood by Mac gamers, and they will continue to enjoy Westlake products.