Microsoft has relaxed its notoriously complex Windows Software Assurance licensing scheme, making it somewhat easier for enterprises to deploy Desktop as a Service scenarios, changing the model from per device to per user.

The new Windows Software Assurance per User and Windows Virtual Desktop Access per User licensing options have loosened up Microsoft's earlier, strict conditions that required one license per device.
Now, users can have Windows Enterprise installed on all their devices, or access the operating system from these on a single license.
The changes also mean its possible to use Virtual Desktop Infrastructure access for Windows without further licenses per device.
Earlier, complex licensing requirements led to VDI providers such as Amazon Web Services using Windows Server as the remote desktop, and not Windows 7, 8 or 8.1.
The new licensing model includes several caveats: not all editions of Windows qualify for volume licensing upgrades to Windows 8.1 Enterprise. The primary device used must also be licensed for Windows Pro.
Microsoft is yet to reveal the specifics of pricing and transition details.