It's been covered well enough in the blogs - but this could change quite a bit in the next 6 months.  Let's see how Silverlight and developers take off with these new tools.  Now on Windows, Macintosh, and "Moonlight" on Linux ....

• http://weblogs.asp.net/scottgu/archive/2007/09/04/silverlight-1-0-released-and-silverlight-for-linux-announced.aspx
• http://www.hanselman.com/blog/Silverlight10IsOutAndItSupportsLinux.aspx
• http://www.joshholmes.com/2007/09/05/DancingInTheMoonlight.aspx
• http://blogs.msdn.com/mswanson/archive/2007/09/05/silverlight-1-0-linux-converters-and-swift-3d.aspx