HumanCompiler said:
This depends on how the video creator made the video.  If you get a list of some that are wrong, I can forward them to the content team.
At least
http://channel9.msdn.com/posts/Dan/Bill-Gates-TechEd-Keynote/
http://channel9.msdn.com/shows/Communicating/A-New-Photobucketcom-API/
http://channel9.msdn.com/shows/Communicating/The-TM-Forum-at-NAB/
http://channel9.msdn.com/posts/eliseta/nHibernate/
http://channel9.msdn.com/shows/Communicating/Grid-Computing-at-Layered-Technologies/
seem to be affected.

The idea of widescreen wideos is nice as almost everybody has a widescreen monitor these days but the current ones just don't work as they're supposed to. A quick check revealed that problem appears in both the silverlight versions and the downloadable ones.