There seem to really only be two new major features in JW Player 5.5 though they cite numerous bug fixes and enhancements.
RTMP Fallback Support for HTML5
"Once we introduced support for HTML5, one of the most asked for features was providing a fallback mechanism to handle the case where the primary content source is an RTMP stream. With JW5.5 we have introduced mode-specific configuration settings in the JW Embedder. Now, if you use the JW Embedder, you can customize how the player is configured if it is being rendered in Flash or HTML5. This is a powerful feature for crafting a different user experience in Flash versus HTML5 and makes RTMP fallback a breeze"
A lot of the other stuff changed as well but was deemed much less important. However, I dug through the whole list and pulled out some interesting stuff:
- Place dock in left or right position
- Pluginmode for Flash plugins
- Colorizable PNG Skins
- Draw buttons for default skin
- PNG Skin Fonting
- Bandwidth Switching
- Player SEO (the ticket actually links to ReelSEO, NICE & Thank you!)
If you're a JW Player user you can get the new 5.5 now: Download it.