The MSDN Team Launched Tagging across the entire corpus of the MSDN Library (it is present anyplace that Community Content is enabled) and we are ready for your Folksonomies!
The MTPS Tagging feature enables customers and authors to add and remove visible keyword tags to both topic pages and wiki blocks to improve discoverability of the library content. The ability to add tags to content will be enabled for teams who have opted into the Community Content (wiki annotations) feature in MTPS.
A consolidated ‘tag cloud’ view of all tags is shown on the MSDN Library home page and provides a way to navigate content by associated metadata. The Browse by tags pages enable discovery of content through progressive refinement of tags.
Tags list (http://msdn2.microsoft.com/en-us/library/tags-list.aspx)
Larry W Jordan Jr - Product Unit Manager for MSDN and TechNet Infrastructure Team