Evans Data predicts that in the next 12 to 18 months Silverlight will triple its market share:
http://www.eweek.com/c/a/Application-Development/Silverlight-Adoption-Expected-to-Triple/
The problem with this article is that it doesn’t specify if that means that the 2% market penetration will triple to 6% or if they are talking about the number of Silverlight enabled sites will triple in the next 12-18 months. The driving case for the tripling will be the developer tools. Although a lot of people are having issues with the first release and the beta releases of Expression Blend and Expression Encoder, look for the released second version to add a much needed level of stability and clean code output.