is there an JavaScript event triggered, if a HTML5 video is ready for playback?
Good discussion here...
http://tiffanybbrown.com/2010/07/05/the-html5-video-progress-event/
Especially the first comment.
Basically, this was in the spec and was removed because it didn't exactly go hand in hand with the way media is rendered. Instead, .buffered was added.
Here is an example of buffered in use:
http://hacks.mozilla.org/2010/08/html5-video-buffered-property-available-in-firefox-4/