Probably requires WMV codecs?

Edit:

  sudo apt-get install gstreamer0.10-plugins-ugly gstreamer0.10-plugins-bad gstreamer0.10-ffmpeg

Don't let the names scare you, they refer to the licenses not the quality of the code. Normally these would be detected and installed automatically, but there's a bug that prevents mms:// content from being autodetected.

edit2: fixed codecs, sorry

The asx file is a xml file. Pick out the URL from it, and use mplayer with it.

mplayer mms://a977.l12501352976.c125013.g.lm.akamaistream.net/D/977/125013/v0001/reflector:52976