It works but using Microsoft Media Encoder and that allows transcoding on the fly from any supported format to WMV.
Word of warning it is VERY fussy over what codecs it uses, I'm having problems getting it to work. Basically remove every codec from your computer and install DivX 6.1 (it will play Xvid files too) and the AC3 codec, Should hopefully work then.
It's one step closer though, hopefully once they create a open source transcoding program so it doesnt need the bloaty Media Encoder you should be able to play most formats.