OK.. I have done a couple of short things.. very amateur i know but would like to know if..
A. They are watched by people that normally only listen to my audio..?
B. You think it is a direction i should continue to play with?
C. you think the future of podcasting is in audio or Video?
A) Anyone subscribed to your feed will see the video there instead of the audio, so your base audience will either view them on their computer or possibly add them to their ipod.
B) I think your show, being a documentary approach to the world, is a natural for video. You take your audience to the world of your subject instead of just talking about it, so video can only enhance this experience. Having said that, some of your past interviews might actually be more compelling as audio only experiences simply because one can focus on the content of the conversation more completely without the video. For example one of your recent podcasts took place around a table, an audio experience ( not including your harrowing walk to your car), but your bio diesel episode would have been a natural for video.
C) The future of podcasting is audio and video. Our show for instance is definitely an audio experience. We could add a camera, but if we aren't willing to add footage associated with our topics, there's not much of a point to it, unless you are prone to become infatuated with the lovely ladies of Wake Up AM. (I'll be behind the camera if it ever comes to that.)
Documentally is a show that can really embrace video. Your enhanced podcasts of the past telegraphed this eventuality. Plus your a visual person, so I say go for it.