Your best bet to get the best answer, is going to be to contact a Microsoft Licensing specialist. I'm presuming your using Volume Licensing, in which case here's the contact page: http://www.microsoft.com/Licensing/contact-us.aspx

Yes, MS Licensing is at least as difficult to understand the rules as SQL Server (maybe harder) which is why most everyone will shy away from providing an answer other than "call MS." It's way to easy to get the answer wrong...

Jason