All round good guy, Rodney Buike has posted a reminder:  As of October 1st (14 days away) Windows Datacenter will now be available for purchase through Volume License channels.  There is more more in his post ‘Datacenter and Virtualization Licensing Changes‘ and a snippet from the Windows Datacenter web site is below:

Unlimited virtualization rights: Starting October 1, 2006, new servers licensed with Windows Server Datacenter Edition (and previous licenses with new version rights) will have license rights to run an unlimited number of virtualized Windows Server instances. By simply licensing the server’s processors with Windows Server Datacenter Edition, customers will be able to run Windows Server Standard Edition, Enterprise Edition, Datacenter Edition or a mix of the three editions without having to track the number of virtual machines or pay for additional Windows Server licenses.
 

This [personally] opens up so many questions, for instance how much?  As I find out more I’ll post back  :)