A great but sometimes overlooked resource for Silverlight and WPF developers is the Expression Newsletter. It covers the Expression suite as a whole, but always has good content for Blend, Design and folks writing applications for WPF and Silverlight using VS2008. I like the focus; while it certainly includes Expression tools, it is more about how to get something done - when appropriate authors have no issues jumping out to other tools like VS2008.
Be sure to subscribe before the mid-January newsletter to catch my deep dive on styling the charts in the Silverlight toolkit. Thanks to David Anson and Justin Angel (and the rest of the toolkit team) for keeping me on track with that article.
The current Expression Newsletter (November 2008) is here. You’ll see some great articles by Microsoft folks and MVPs, as well as links to past issues of the newsletter.