It seems that there is just a bit of confusion here, and I guess it's somewhat understandable.
From the wiki...
The above two sections are specifically talking about streaming through progressive downloading. It's a technology that only requires a compatible media player, not a specific streaming server. You can stream via progressive download from ANY web accessible directory.
As you have seen, the Darwin streaming server does not support *.wmv. Here is a link to details about Darwin: http://www.publicsource.apple.com/projects/streaming/StreamingServerHelp/pgs/ss12.html
I did a lot of research about this stuff the other night, because I was hoping to use Darwin as a relay server. I wanted to upload a single stream from winamp on my machine to Darwin, then have a couple live streams for friends, ala SHOUTcast. No luck in my research so far.