Microsoft has just released an update to the Microsoft Certified IT Professional (MCITP) with the creation of Business Intelligence Developer credential. It looks like you only need to sit two exams to become a Business Intelligence Developer.
This qualification is a step up from the Microsoft Certified Technology Specialists in Microsoft SQL Server 2005 Business Intelligence (MCTS: SQL Server 2005 BI).
The training material is available but the exams are not available until early 2007. It might be a good time to start looking into getting this certification.
MCITP: Business Intelligence Developer
MCTS: SQL Server 2005 Business Intelligence