VSTO Team Blog has Moved
The VSTO team blog has moved to https://blogs.msdn.com/vsto , and the RSS feed is https://blogs.msdn.com/vsto/rss.xml. The team blog is an interesting source of insider information on VSTO, I'd encourage you to subscribe.
Some cool recent posts over there:
Developing an add-in for multiple versions of Office (Mary Lee)
Share a Ribbon Customization between Office Applications (Norm Estabrook)
New Power Tools - Ribbon IDs Tool Window (Kemp Brown)