Sliverlight is becoming wider adoption than years before. I have been viewing showcases on the sliverlight website today.
In general, the UI looks rich and flexible by using this technology.
Some sites I have tried:
Renlifang: http://renlifang.msra.cn/news.aspx from MSRA
And It also opens new opportunity for ISV to create Sliverlight UI control.
So do you use Sliverlight now?
If you are are developer, when designing a new web UI application, using Sliverlight is worth consideration.