In followup to the news of an in-house port of Unreal 2003, Inside Mac Games posted a followup Q&A with Epic Games which reports that Mac UT 2003 is aiming for Christmas 2002 release.
Q&A with Westlake Interactive provided reassurance that the Epic Games in-house port would not hinder development of future ports based on the UT 2003 engine.
Correction: Originally mistyped as Christmas 2003. Apologies.