My fear is that mastery around a topic will cause you to be useless in every day support of SQL Server. Sure you are great at what SQL Server should be but are you able to adapt and think outside of the box. All to often I have seen certifications build a very heavy box around a person and they cannot think outside of it. They cannot be dynamic and use their knowledge to get better.

alternately... are you a master in SQL Server 2000, 2005, 2008 and R2. If so I don't believe you. Mastery of one, maybe two sure... especially when the base is close but mastery of all currently used versions just isn't feasible. Sure not much changes but if you are really getting paid to work and not just learn and research I don't think true mastery is in your future. You must have hands on to master a skill.