Looks like a great product, and I will second the parent comment.
One thing they teach at YC, and in one of pg's essays (http://www.paulgraham.com/investors.html), is to present a story instead of a list of features. That way you answer the question of "Why would I use this product?" simultaneously to answering "What does this product do?".
I love that approach (my weblog is called "Story-Driven" after all) because it automatically breaks technical people out of a taxonomic, procedural mindset. So many descriptions of things are on the order of "well, it's a set of pliers with a light on it" instead of "it's how I change fuses in my rusty fusebox in the middle of the night."
You can't emphasize enough to people to tell a story, and the screencast is a great crucible for whether you have a good story to tell. Screencasts aren't appreciated enough for the way they've helped people understand concepts that are a little more technical than they normally would sit still for.