Nikhik in his recent blog explains how to dynamically select a theme from multiple themes in Silverlight 2 applications, e.g. based on a user's profile. This improved feature addresses several shortcomings associated with the StaticResource approach. However, it does not support change of the theme on the fly. In other words, themes have to be pre-built using tools such as Expression Blend; they cannot be created and applied programmatically in the application.