MPDN v2.43.0 brings about a new feature that allows player extensions to add support for custom source filters. I've added a Youtube source provider that uses the 3DYD Youtube Source Filter
http://ys.3dyd.com/home/ to stream video from all (youtube, vimeo, etc.) the sources it supports.
You'll need to install the source filter seperately for it to work.
For maximum quality, you should set the 3DYD Youtube Source Filter to "Enable DASH Streams" and "Best Quality" for resolution.