Possibly a 25% cost increase -- only for servers with over 8 cores per processor -- and more revenue for Microsoft. According to Karl Keirstead, analyst at Deutsche Bank:
"Microsoft announced last week that it will change its pricing model for its Windows Server and System Center products, two of the largest contributors to Microsoft's big Server Product business, to a per-core model from a per-processor model. Microsoft claims that the intent is to align the Windows Server pricing model with Azure and SQL Server in order to facilitate a transition to Azure, but the de facto price increase also serves to boost FY17 Server Product revenues....
"The change impacts customers running compute-intensive servers with a high core density (over 8 cores per processor). For these deployments, some industry analysts are saying that pricing will rise by 25% under the new model. Customers will see no pricing change on servers running 2 or 4 processors with 8 or fewer cores per processor. Microsoft also added new features to the Datacenter edition of Windows Server, which could create a shift to this more expensive edition, and will also switch its System Center product to per-core pricing. The changes take effect when Windows Server 2016 and System Center 2016 go GA [general availability] in 3Q16, hence the revenues boost will start in FY17 (phased-in upon EA renewal and net new license purchases)."