Video online should not look like a TV report, with a talking head.
Angela Grant, who shoots video at the San Antonio Express-News, says there are three things that make a good video:
Here is something you "just have to see": Paraplegic Dog (Spokesman-Review)
Make sure you watch it to the end.
The PowerPoint is on your CD.
If you have time and the desire to teach students a more complex editing program than WMM or iMovie, of course you should do it. But getting them started with a simple, free tool is better than not teaching them any video editing at all.