I was chatting with Ken Levy a couple of weeks ago about what he's up to now (he works for the Visual Studio Extensibility Team) and he pointed me at a great resource that he's put together with the guys from CoDe Focus Magazine.
VSX CoDe Focus magazine is now online at http://code-magazine.com/focus/vsx. Microsoft sponsored this special edition of CoDe Magazine on the topic of VSX. The entire 76 page magazine is available online in multi-page HTML format and also as a PDF download (13MB). Printed copies of the magazine will be available in late October at various developer events and mailed to many existing CoDe magazine subscribers.