Am I the only person who hates screencasts and finds them to be almost the worst possible way to make tutorials or even put together a demo? Like tutorials in a game, I find them terribly ineffective for teaching.
They're useful for some people. I don't think they should replace documentation though, and I think they really should be accompanied by the script.
Some very good advice in there though.
Still, I think a lot of people really don't understand the massive workload it takes to get a good screencast done. It's a TONNE of work. (As in metric tonne because it's bigger.
The audio alone is extremely difficult. Not many people will go to a professional recording studio to have it done though. And if you don't, you need good tools to work with the audio, and not just some 2-bit audio editor.
Timing is the most important thing, so you need to have a good video editor.