OK, here's my brief report on using the "make a video" on PowerPoint.
First, I'm on a Mac. But, this may be useful to all.
The video that PowerPoint makes is a .mov. That is, it's Quicktime. Sounds good, right? Well, if you want to record a very, very, very rough video using the clicker to time the slides, this will work. But, it will stink. You need to edit.
My advice is to purchase Quicktime Pro ($30--which is available for Windows, BTW.) Convert the PowerPoint into individual slides, import the slides in order into Quicktime Pro, turning that into a movie (it's fast and easy, read the directions) and then edit that movie in either Quicktime Pro (more powerful than it first looks--check out the options) or, if you have it, iMovie. At the end, you can put your audio on it.
This advice even applies if you have a Mac and iMovie. For reasons that probably having to do with PowerPoint being MS and iMovie being Apple, I couldn't edit the .mov made by PowerPoint in iMovie. But, I could use iMovie after pushing it through QT pro as I outlined above.
Making a movie via PowerPoint may sound wacky to some but not to me. If you're a whiz with PowerPoint or you have a lot of PowerPoints you want to put onto YouTube, this might get you there.