Oh, that's really neat! Just a small idea, if you don't mind: perhaps you could have a list (either curated or crowd sourced) of eventual topics to be covered in future screencasts so people can upvote or downvote them according to their preference? This way you'd know your audience and they'd tell you in advance how to drive the production of the screencasts. Anyway, I've shared it with friends already and have also subscribed for the next screencasts. Good job, Justin!