Maybe this is a silly question but if we can shoot uncompressed RAW shouldn't it be possible to shoot uncompressed JPG video? Wouldn't this allow for a lot more FPS and greater resolutions?
Short answer, no. First off, JPEG is lossy, meaning there isn't a true uncompressed JPG. Are you talking about Motion JPG or getting JPG images that work similarly to the ones taken in photo mode? There have been a lot of different threads that have explored alternatives to H.264 and RAW, currently what appears to be the most promising is the 10 or 12 bit RAW possibility that is being discussed. It would allow for greater frame rates and resolution, but not "a lot more."
http://www.magiclantern.fm/forum/index.php?topic=5247.0
http://www.magiclantern.fm/forum/index.php?topic=5601.0