Today Adobe released an update to the FLVPlayback component (v2.5.0.15) for Flash CS4 and Flex 3 (yes, Flex is supported!).
This component has numerous bug fixes to make it more robust for streaming including support for Dynamic Streaming (multibitrate) and DVR. A new Devnet article is also available discussing these new features: http://www.adobe.com/devnet/flashmediaserver/ (note Part 2 of the DVR article by David Hassoun).

We also released the new DVRCast application that makes it easy to add DVR-enabled live streams to your website using Flash Media Server 3.5.

There's much more info on the new features on Kevin's blog.

You can download both tools from: http://www.adobe.com/go/fms_tools/

I can't wait to try these new features - just need to wait for the next suitable live event :-)
I think it is highly likely that this is the last update to the FLVPlayback component we will see as the upcoming Strobe framework is likely to replace the efforts made my the component. Love it or hate it, the FLVPlayback component helped countless Flash newcomers to get their video content online quickly. If this is indeed the last update then it will go out with a bang as these new features are pretty cool - and we've got a Flex version thrown in too.