I know I am late to the game with this post (sorry, been busy...) but it's nevertheless worth noting that Flash Media Server 4.5 is now out.
So what's new in this version? Most notable is the support for HLS streaming - with this FMS is now capable of delivering live and on-demand video to devices and HTML5 browsers supporting the HTTP Live Streaming (HLS) and HTTP Dynamic Streaming (HDS) formats, which most importantly includes iOS devices.
Now despite what some sensationalist 'tech blogs' would have you believe this is not 'Flash-free Flash on iOS'. Instead this new feature offers the possibility to deliver a particular piece of video content to more than one platform via FMS. The server achieves this by repackaging the existing video file into a compatible format for delivery over HDS and HLS. This means that publishers don't have t worry ahead of time about the platforms they want to target and can now deliver the same piece of media to both Flash and iOS.

Check out FMS 4.5 and download the free developer edition from Adobe's website.