I have just tried 'Twonky Manager' and yes I does have 'Play to' or DMC (Digital Media Controller) ability, But there are significant hurdles. Interface is very cumbersome and it did not work on some devices. For example it was able to push content to WDTV Live unit but could not push MP3 file to Pioneer X-SMC4 unit which both Win7 and iTunes had no problems with. Also sending files to Pioneer unit caused Pioneer unit to freeze and it needed a restart before it can accept files from either Win7 or iTunes.
Also 'Twonky Manager' was very flaky in operation. When I sent files to any DMR unit, it caused 'Twonky Manager' application to stop responding for 5 seconds or so. Very annoying, reminded me of Windows 95 era software. So I guess I would stick with iTunes or Bluetooth A2DP profile for pushing audio files.
However few Android based DMC apps worked fine, even with Pioneer unit, and without pauses and freezes.