Xuggle (http://xuggle.com/) has been available in beta for a little while.
It allows streaming servers like red5 (http://osflash.org/red5) to manipulate streams in realtime.
Some interesting things that makes immediately possible :
- Serverside live stream snapshots
- Much simpler integration between web based flash clients and VoIP gateways
- Capturing and live streaming of TV content
- Mind bending multi user dispersed video editing/manipulation
