CIT continually receives feedback about alternatives, particularly about recording slideshows directly.

Note
Support for these are provided by the software companies directly.

Here are a few methods:

Windows

Mac

Info

PowerPoint for Mac

2016 - there is no save presentation as a movie file feature
2011 - save presentation as a movie file does not include recorded narration (refer to notes)
in short, recording then exporting a video is not possible in PowerPoint for Mac.