Currently I do not know of any Asterix integrations. The main issue is with the Nelly Moser audio codec that the Flash player client uses for audio compression. There are no known open source implementations and the licensing costs are quite high. This is what is needed to send audio data back and forth between Wowza Pro and Asterix.
I don't have any experience with ASAO decoder from NellyMoser. I did find an open source decoder at Google code (
http://code.google.com/p/nelly2pcm/). I am not sure of the legality of this decoder but it is out there.