I think Silverlight is a great technology that can be use to create great applications, or as a migration target from Visual Basic 6, Powerbuilder or Windows Forms apps which can take advantage of a very simplified deployment approach.
And use Artinsoft/ Mobilize automated solutions (see http://www.artinsoft.com/visual-basic-6-or-csharp-to-the-web.aspx )
Deployment is as simple as just publish your SL application on your intranet and your clients just need to press F5 to have the latest SL version.
Silverlight provides a good balance between ease of development and platform features(XAML and .NET and Visual Studio).
Silverlight can run cross-platform. (On Windows and Mac using the official Microsoft implementation and on Linux using Moonlight.
Support For Silverlight 4
Support For Silverlight 5
NOTE: Moonlight provides support for 32 and 64 bit Linux. It supports Silverlight 2.0, and some features of silverlight 3 and 4, but is not currently an active project.