this is a question we often get asked:
What is the best way to license Windows Server and Exchange Server for testing purposes?
Development or testing environments are probably best licensed through Visual Studio 2005 licenses and the Application Lifecycle Management tools, ie VS2005 Team Suite products. These products have development-specific licensing agreements that have different guidelines for these environments. Outside of these development-specific agreements, products need to be fully licensed within the guidelines of the Product Use Rights (PUR) or a licensing agreement. Remember though to get Software Assurance with these licenses as then you can upgrade to the new versions when they are released.
I'd love to hear any more of your questions - email@example.com
talk to you soon,