Thanks for the replies guys! I agree about the altnerative to RealPlayer, I would be concerned about copyrights, but I appreciate the suggestion! 
I may try to take a few of the files and convert them, IF I can. And I think the suggestions regarding spicing up the artistic aspect of the Workshop are dead on. In fact I think I should make it so that the artistic component is only related to, but not dependent on, the lecture material. Very little of it is visual, but I found seeing a real person writing the terms on the board to be very refreshing and useful.
There will be probably 2 Workshops before this series starts, so that gives me time to put things together and think about the details. If you have any more suggestions, I strongly encourage you to post them here! 
Thanks guys!