This is a new licensing program that will be available on the January 2014 SPLA price list. It is aimed at Service Providers who run heterogenous environment – that is environments with a mix of Operating Systems such as Windows, Linux & Unix.
It is licensed in a “Host and Guest” model – the Host license covers the hardware and you will then purchase a Guest license for each Windows VM you wish to run.
Host SKU: Includes Windows Server 2012 R2, System Center 2012 R2, and Windows Azure Pack, host capabilities and rights to manage all guests
Guest SKU: Includes Windows Server 2012 R2 guest capabilities
For more info, check out my good friends over at Licensing School: