One of the things I hear a lot about it wanting well-designed control templates/styles for developers to use in Silverlight (and WPF). As someone with that missing creativity gene, I agree. While we wait for some of these galleries to emerge (and designers to contribute), there is some hope for the rest of us today.
For WPF developers, there has been a commercial resource available (not free) in the templates provided by XAMLTemplates.net. They provide various styles available for purchase for WPF templates and styles.
There also have been some emerging in the Silverlight.net community gallery (look for Dark Skin for Controls) as well (and I encourage anyone to post theirs to the gallery as well). One recent one (prepped for Silverlight 2 release) is one of the UK’s user experience consultants, Dave Crawford. Dave just propped up a blog on MSDN and his first post is his contribution to the Silverlight control template world: Dave’s Glossy Controls. A preview of the included styles shows some subtle templates to provide a distinctive interface:
Dave released these under Ms-Pl as well and demonstrates in his blog post how easy it is to change some of the colors in his templates as well as how easy they are to use in Expression Blend. Thanks for contributing Dave!