Looking at blogs.technet.com for review time and had to slice the blogs by internal team/org, so thought I would share.
Security Guidance (MSS)
Enterprise Engineering Center
Microsoft Services Labs
Two more from me:
I'd also add mssmallbiz as a biggie but they are over on the MSDN side of things.
As for the blog site - once nice thing would be the ability to filter by default language. "recent posts" page shows posts regardless of the language which makes it a little hard to get a quick glance at what Microsoft techies are up to.