Are you using Microsoft virtualization technologies in your environment? Do you need/want to get certified on those technologies?
Then take a look at the just released (August 25, 2008) certification exam 70-652 TS: Windows Server Virtualization, Configuring.
We also have a single exam certification MCTS: System Center Virtual Machine Manager certification. The exam number is 70-403: TS: System Center Virtual Machine Manager, Configuring. The exam is slated for release in late December 2008.