FWIW if anyone else is seeking answer to this question: The
answer is no. Flash Media Server does not stream in a format that
iTunes/WinAmp will recognize. My understanding is that the RTMP
protocol is proprietary to Adobe products. Yes, technically the
stream is an MP3 stream, but it actually doesn't come out from the
FMS as a plain MP3 stream that is in a Shoutcast or other
iTunes-friendly format.
If anyone else disagrees, please, please, please, say
something. The Adobe support guy that I talked to may have had it
wrong.