I’ve had a couple of people report that they didn’t want to install the quicktime plugin just to watch the screencasts. A couple of other folks reported that they were just unable to get the videos to play online. As an experiment, I’ve tried to convert this last video in Flash Video, and use a cool Flash player I found. I’m thinking Flash is even more common than Quicktime so there should be less problems?
It’s even got a cool "full screen" feature and volume control, so that’s a bonus. The file size is like 3 times what it was as a quicktime video though, and the quality might even be a little lower, so that’s an anti-bonus.
Personally i like the Quicktime better, but you can’t go wrong with a nice looking flash player. If you have the bandwidth, space, and time it might be nice to have a flash and quicktime for every screen cast. Flash is nice for watching online, but I always download the Quicktime videos so i can watch them later where and when ever i want to.
While Flash is ubiquitous on most PCs its worth keeping in mind that for maximum compatibility with other devices (such Nintendo WII) you are looking at Flash 7 being the norm which means some of the cool compression bits have to be left of. On a side note christ I noticed your using SWFObject which is cool but given your on a Jquery quest you might find http://jquery.lukelutman.com/plugins/flash/ useful.
Also keeping the ability to download for offline viewing is a nice idea.