I have
Firefox 22
VLC media player 2.0.7
VLC Mozilla Web Plugin 2.0.6
However if I click a link to a video, it still attempts to download it instead of streaming it. It only streams it if I open VLC and
Media Open Network Stream
It appears this is a problem for files with MIME type
application/octet-stream
video/quicktime
Use VLC Web Plugin (in Firefox)