File Reference runtime access -- Bring users into the experience by letting them load files into your RIA. You can work with the content at runtime and even save it back when you are done through the browse dialog box. Files can be accessed as a byteArray or text using a convenient API in ActionScript without round-tripping to the server. You no longer have to know a server language or have access to a server to load or save files at runtime.
That's yet more big news. Saving actual files locally? Load files into the app without going through a server first? WOW! Combine this with video downloads and P2P...
Hank Williams even thinks that this technology could kill CDNs. I'm not sure if I agree with that totally, but it will have an impact no doubt. It remains to be seen how restrictive or open this new API really is. But we will have fun over the coming months, that much is clear.
Oh, and it looks like I was right about the multi bitrate support too. :-)