Heh, I had a definite pipe dream of doing a pretty much direct clone (dumbed down from SITH2) using DirectX so that it could run on the Xbox. The whole issue of re-writing everything to run on ~ DX6 (roughly what the Xbox runs on from what I understand) wouldn't be too tough, but physics are where the real issue lies. Sure, there's always the possibility of using an open source canned physics engine, but then there's still the issue of calibrating every little subtle nuance to match the original physics.
Honestly, as much as I would hope for an completed open source JK engine, we'd have better luck waving upwards of 250,000 US dollars in Lucasarts' face to buy the old engine outright, then upgrade from there. Yes, even then we'd likely rewrite the engine, but we would have the original source as reference.
Before anyone gets their hopes up, I seriously doubt Lucasarts will sell SITH, even for 250,000. And honestly, I think the issue lies in the fact that they used the engine for Paramount's Indiana Jones game. I'm no legal expert, but that seems like enough to have them step back and play it safe. I still hold onto the hope that someday 3-6 years down the road they'll release it, long after contracts have expired and they 100% own any and all rights. As of now the whole "you can't mod Indiana Jones" EULA issue will always make them play it safe.
-There are easier things in life than finding a good woman, like nailing Jello to a tree, for instance
Tazz