Unreal Tournament May Still Support Console MODs news from 1UP.com:

Part of what makes first-person-shooters on the PC so appealing is the ability for aspiring designers, artists and programmers to develop their own character models, levels, weapons and whatever else their mind can conjure up, often times using the same tools the developers themselves did. That’s never been possible on consoles, but Epic Games has indicated in the past this is part of their goal for Unreal Tournament 3 — first on PlayStation 3 and PC and now, it seems, on Xbox 360, too.