After seeing a few jobs on Elance related to JW Player I decided to give it a try and see what all the buzz was about. I'll have to say it seemed to have been a big time sink. The only version of the module that works with the latest 6 version of JW Player is 7.x-2.x-dev and it needs a lot of work. I couldn't even get the player to load in any of the 3 major browsers.
I'll follow the discussion in the issue queue and see what develops. A lot of people seem to want this to happen, but meantime there are better modules to do the same job.