The MCAD exam set has now been retired (May 2009). Candidates are no longer able to achieve the MCAD certification. The upgrade exams for MCTS and MCPD will follow shortly. Candidates are still able to take the individual exams 70-536 and 70-548 etc. to achieve their MCTS or MCPD
Candidates who have started the MCAD certification path are advised to start studying towards the alternative and more up to date MCTS and MCPD paths. These target the .NET framework 2 and 3.5 using Visual Studio 2005 and 2008. These certification paths are shorter than the MCAD and are targeted more towards you area of expertise.
Remember to check that your upgrade exams are still available, without them, you must take the entire certification from scratch. This entails paying for each exam instead of paying for the single upgrade exam. So that's both time and money you'll save yourself by taking the update exam
The following exams were part of MCAD:
70-305
70-310
70-320
70-315
70-330
70-340