While we play a game, replay data is stored somewhere.
- If it's on the hard drive, it won't be hard to create a program allowing to live-stream the replay while it's being built.
- If it's stored in RAM before getting transfered to hard drive (in LastGame.DGReplay), I dunno how to catch it but it must be possible.
Live replay have the advantage of being almost real-time, letting people watch wherever they want during the game, and a comentator can create a channel on vent/teamspeak/mumble to provide real-time commentaries. People have been doing this for a french competition on Supreme Commander and it worked great. If someone can say me where the replay data is stored during the game, i think i can develop the software.
About video encoding, the best quality/size ratio is obtained by using x264 (http://x264.nl/). It has to be run on command-line, but it's not complicated, gives great quality for small size, and uses all the cores of the CPU.
For file hosting FileFront is good, but youtube too as long as videos are uploaded in HD.
For video capture, imo FRAPS is the best. If you record at 30 fps, in a reasonable resolution, you'll have no problem recording a full 40min game with 100 Go of free space on your drive.
PS: I can provide a registered FRAPS v3 <.<