There is this license tool that comes with Windows Automated Installation Kit and is installed by default. This unheard of tool is called Volume Activation Management Tool (VAMT). With this tool you can scan for instance all computer  objects in Active Directory to see the license status of all client machines as well as servers.

You will see what type of key (KMS/MAK) the machine is using, transition licenses from MAK to KMS, see if the license is activated on each machine and you will also be able to identify which machine is the Key Management Server.

The current version of this tool is version 1.2 but 2.0 is coming. Version 2.0 is needed to activate soon to be released Office 2010  but it also sports new features such as a command line interface for automating scans without using the user interface.