Works great!

I tried pushing stuff from the N9 internal server and a windows media player instance to another wmp instance and my RX-V771 receiver. Worked without problems.

I like how it shows what media is incompatible with selected renderer because my media libraries are sometimes a mess. I hope you plan to check which renderer can play/show the selected media in the "share over UPnP"-feature? (I hope I understood that correctly)

Keep up the great work! Thanks!