A copyleft license [1] could probably eliminate most invasive proprietary "value-add". Though that might hinder adoption, being just a dump pipe or a box mover isn't very profitable. Hopefully companies are getting desperate enough to give up on Apple-like profits.
1. A license that requires derivative works to be distributed under the same terms
In response to the change of license, Richard Stallman of the Free Software
Foundation says, "I agree. It is wise to make some of the Ogg Vorbis code
available for use in proprietary software, so that commercial companies doing
proprietary software will use it, and help Vorbis succeed in competition with
other formats that would be restricted against our use."
You may not be able to just feed Flash WebM files: Adobe has only committed to supporting the VP8 codec, not Vorbis or Matroska (http://blogs.adobe.com/flashplatform/2010/05/adobe_support_f...). I wonder if the primary purpose Flash video will be making timeshifting impractical for normal people through weird formats and protocols.
1. A license that requires derivative works to be distributed under the same terms