It was a bitch to get FileReference working as I wanted it to (look ma, no sessions!), but it was well worth the effort. The sample uses an authentication-token based system instead of the less secure hack of tacking the session ID on to the request URL method (yuck!)
This is big: Adobe is removing restrictions on the use of the SWF and FLV/F4V specifications as part of their new Open Screen Project 2008.
When Mark Doherty emailed me to tell me about his post on Adobe's Open Screen Project 2008, I wasn't expecting such an important announcement.