Via Twitter, I stumbled upon a link to this newly updated pdf from Joseph Sack and David Ikeda who are instructors for the Microsoft Certified Master: SQL Server 2008 program at Microsoft. I have previously written about the program here. The executive summary is that it is a very difficult and expensive program to complete. Currently, there are only 60 MCMs in SQL Server in the world, so it is a pretty exclusive group.
Assuming that you may not be able to make that much of a commitment, it could still be very useful for many DBAs to start going though the pre-reading list provided for the program, since you are almost guaranteed to learn something about SQL Server. If you are even more gung-ho, you could complete the MCITP: Database Developer certification and an MCITP: Database Administrator certifications (which are prerequisites to being accepted into the MCM for SQL Server).
Speaking of gung-ho, this post reminded me of the Marine Corps Professional Reading List, which began back in 1989. This list (which is organized by rank) is designed to give Marines a very solid foundation in military history, logistics, tactics, strategy, etc., and it includes many extremely valuable resources. I was a Sergeant in the Marines, long ago, and I have read many of the books on this list.