I've been following the WindowsClient.NET blog for some time now and have been really impressed with some of the content. In addition to some great tutorial videos on the site itself there have been some really good links to code fragments - such as:

• Dragging and dropping between WPF ItemsControls
• Series showing the magic of adorners (I've been using these a bit) and creating your own design surface
• Series on Building Business Applications in WPF

Great content - great feed.