Essentially, this was the topic of my webinar yesterday. Where I presented to video producers some important functions in the PowerPoint program and how to transfer or move a PowerPoint presentation from your computer into a video editing application or device.
Then the real focus was how to move or convert a PowerPoint presentation over to a video editing application or appliance (like the Casablanca video editor).
I demonstrated clearly why your better choice over JPG is to export slides as PNG files if you are exporting single slides to re-create the presentation in your video editor, I also showed the easy use of 3rd party conversion applications - built just for this purpose like the ImTOO PowerPoint conversion tools.
And I demonstrated how to export a PowerPoint presentation as a video file directly from the PowerPoint application itself. A note of clarification - in follow-up research it turns out this option to export as a video/movie file is only available on the 2010 and higher versions of Microsoft Office if you are on the Windows platform.
If you are using Microsoft Office/PowerPoint on the Mac - you'll find that option to export as MOV file even going back to the 2004 versions of Microsoft Office (If you can explain that logic to me, please let me know in the comments below...how Microsoft did not include this option until 2010 while it had it available to Mac users for 6 years prior)