Eihrul has announced that he would start working on a project called Tesseract. It's not supposed to replace sauerbraten but it's kind of like an experiment.
Tesseract is a whole new lighting system that introduces dynamic lighting. Since the sauerbraten lighting system was basically a copy of the Cube lighting system, with some additional features, it has never had dynamic lighting.
Check out the forum post here,:
http://cubeengine.com/forum.php4?action=display_thread&thread_id=2534The github repository:
https://github.com/lsalzman/tesseractAnd a youtube video demonstrating this new system:
http://www.youtube.com/watch?v=ZkFT1ra2w-AThis new lightning system looks very cool and hopefully it could be included in an official release of sauerbraten.