http://igmdb.org/
Their quake recorder is FTE, so it'll capture vanilla+fitz+dpp7+qw etc demos.
Getting the maps onto the server is more of an issue.
FTE (and I assume DP but I don't know the details for that) has a fun trick that allows it to play back demos at a variable framerate, such that you get one frame exactly every 1/60th or whatever a second regardless of resolution or performance sapping rendering effects etc - it just takes a bit longer to capture every frame (or possibly less, capturing faster than realtime), otherwise known as offline rendering.
FTE also has an ffmpeg plugin that can be used to directly capture the video to pretty much any format you want, in theory. It doesn't really allow for commentary though (unless its pre-embedded into the demo with voip).