Review my site - Shiftpop.com
rrhyne: Second dropping the 'Casts' terminology. I would go with webcasts or streams. I would use google's keyword suggestion tool and find out what people are using to search for webcasts, then use those terms.I think you'll loose initial users people who don't get the functionality with the drag and drop.I like your design, but for the intro tutorial, I'd simplify it greatly, using less graphics. It seems too much like a video I didn't choose, which I was ignoring at first.Good luck!