Although It may be used by people wanting to use a new gadget and effects for the sake of it rather that any creatively thought out broadcast and spammers, video has a real place in blogging, Video comments is a exciting technology with goos potential in the right hands.
It could be used for lively debate and highlighting important issues.
Chapter encoding may work or some type of voice recognition system to wade through the waffle but eventually credible contributors should come to the fore

To run video reliably especially QT you need need to upload js file to your server and get a good plugin. Also when encoding your video file make sure its optimized for streaming and fast start otherwise its a long wait for the end user