In April we personally heard from Epic Games that they weren't certain when their external contractor (a.k.a. Ryan Gordon) would have it done. A month later it appeared UT3 for Linux was dead, but two days later Ryan Gordon said the game is still on its way. Since then, there has been no new information to report.
With it being several months since last hearing anything on the matter, this morning we decided to see if Epic Games had anything new to say. After firing them off a brief email, there was a quick response by Epic's Steve Polge, the lead designer of Unreal Tournament 3.
The UT3 Linux client is still slowly being worked on, but we don't have any estimate for a completion date.
Wow, nearly two years after the game was released for Windows, there is still no sign of when it will be done for Linux. Ryan Gordon is not a novice developer and it should not take nearly this long, especially with his past experience on porting Unreal engines to Mac OS X and Linux. Whatever the case may be, Steve still claims that it's being worked on. Will we see the Linux client this decade?