I think screencasts and video blogs are an exciting way to show off new product capabilities. Others think so too.
We've had a lot of demand for the Office 2007 screencast virtual tours on MSDN and Channel9. These are short, highly targeted features that show how to do a specific developer task in Office.
Take a look at this excellent post by Erika Ehrli, MSDN Office Development Center site manager. She walks through the steps of creating a video screencast and shares them with us. Thanks Erika!