Good SQL Server Blogs

SQL Release Services Blog
http://blogs.msdn.com/b/sqlreleaseservices/

CSS SQL Server Engineers
http://blogs.msdn.com/b/psssql/

SQL Server Engine Tips
http://blogs.msdn.com/b/sqltips/

Microsoft SQL Server Development Customer Advisory Team
http://blogs.msdn.com/b/sqlcat/

SQL CAT(Customer Advisory Team)
http://sqlcat.com/

SQL Server Storage Engine Blog
http://blogs.msdn.com/sqlserverstorageengine/

Tips, Tricks, and Advice from the SQL Server Query Processing Team
http://blogs.msdn.com/b/sqlqueryprocessing/

SQL Server Performance
http://blogs.msdn.com/b/sqlperf/

SQL Programmability & API Development Team Blog
http://blogs.msdn.com/b/sqlprogrammability/

Euan Garden's BLOG
http://blogs.msdn.com/b/euanga/