The only way I succeeded was with Remote Potato combined with Remote Media Center (Android). It lets you play .wtv, dvr-ms etc also music, pictures and all kind off movie formats.
You can even use the EPG to program tv-recording. With the commercial version I can also watch live TV.
MediaPlex is another option I tried with different results, but it uses al lot of my CPU resources (only dual core) and is not as smooth.
Another combination is MediaHouse UPnP/DLNA (Android) with Twonky (Android) on my SG2. Twonky by itself only plays a few formats, not even AVI, so I installed MediaHouse that makes it possible to use e.a. VPlayer over DLNA. Drawback, can play everything except .wtv, but it uses very little resources on my PC.
So I end up with Remote Media Center for .wtv WMC-files and EPG and DLNA by MediaHouse for other formats as this runs very smooth.

Tried to auto convert .wtv to dvr-ms, runs OK, but takes a heavy load on my CPU - combined with autoremoval of adds.