I think Silverlight is pretty much a dying breed. The only application that I can think of that actually uses it successfully is Netflix and that's to put DRM on their videos. When the streaming business first started, anyone with the link to the video could watch it regardless of a membership, so they had to put a clamp down on that really fast.

If Silverlight is dropped like Adobe has dropped Flash support for mobiles, I'm not sure what Netflix will do.