ContentPresenter.com is a free WPF tutorial resource that Lee Brimelow created to help interactive designers learn this exciting new technology.
These tutorials are primarily geared for interactive designers who are used to using tools like Flash.
WPF Disciples is a blog which features some of the most interesting topics that a group of WPF addicts chat about.
This blog is a way for WPF developers and fans alike to get the best of their group discussions without having to be in the group.
Petzold Book Blog is a blog by accomplished programming book author, Charles Petzold.
While it is not exactly a WPF-focused blog, Petzold has written enough XAML and WPF-related blog posts which are worth reading.
Josh Smith on WPF is a blog dedicated to WPF. Josh Smith is an MVP [See Josh's MVP profile].
Nibbles is a tutorial site covering Blend, Silverlight, and WPF.
theWPFblog is a blog on WPF by Lee Brimelow. Though not actively updated anymore, the blog features lots of WPF code samples.
WindowsClient.NET is Microsoft’s community site dedicated to Windows client technologies such as Windows Presentation Foundation (WPF) and Windows Forms.
LearnWPF.com is a Windows Presentation Foundation (WPF) community site.