My post on wowza forum (http://www.wowzamedia.com/forums/showthread.php?t=9576) was deleted by JohnATX today :).

Question:
"We are also in need for Wowza pushing a stream to FMS. Please let me know if there is any such functionality or will be on the horizon."

Wowza team replies:
- "I've sent you a reply off forums."
- "I'm happy to discuss all the details of this with you offline"
- "I will discuss your unique case with you through that ticket."

Possible solution:
You can use any RTMP Client API to pull stream from one server and push it to other (or many) server. Sample code (based on commercial library) is available at http://www.smaxe.com/source.jsf?id=RtmpRetransmitter.java

Update from Sep.21:
Wowza provides 'Push' AddOn http://www.wowzamedia.com/forums/showthread.php?t=10401