We’ve just posted an article I wrote that compares the video RSS capabilities of iTunes and Democracy Player: Video Podcast Shootout.
As I say in the article, this comparison is only with respect to video. iTunes is an excellent audio player and audio podcaster, but we happen to think that we’ve got them beat for most video situations (syncing video to an iPod being a notable exception).
Please take a look and let me know what you think, I’d be happy to add new points on either side: nicholas@pculture.org.