I'm not a coder and I lead OpenArena (The leader = coder requirement is a farce). I only submitted a few .patch files towards OpenArena's code. Though right now OA has only one 3d artist - and that is me. And that sucks because i've been lacking a lot of free time lately You see Free time makes the OSS world go round unless you're corporately sponsored with funding, which I don't intend to get since no monetary amount will give me 8 hours of blender fun daily.
Unfortunately the hobbyist artist scene has minimized itself to HL2 mods, UT2k4 mods (even less so) and 2d pixel art for indie hipster games. The bustling period of generous art help has ended a long time ago (2003, when Tremulous, Urban Terror and World of Padman were well far into asset production). Or they got jobs. In this economy spare time can't be spared, so don't blame them.