Microsoft has made available the Release Candidate of Service Pack 1 for Windows Server 2008 R2 and Windows 7.
Service Pack 1, which is now feature complete will introduce two important new features: Dynamic Memory for Hyper-V and the RemoteFX technology for Remote Desktop Services which Microsoft acquired from Calista in January 2008. The final Service Pack is still expected for H1 2011 as reported by virtualization.info in July this year.
The most interesting news here is the support for Dynamic Memory for the Standard and Web editions of Windows Server as reported by Ben Armstrong, Virtualization Program Manager at Microsoft
Dynamic Memory provides the ability to pool available memory on a physical host and dynamically make that memory available to virtual machines running on the host, based on current workload needs in the virtual machines. Dynamic Memory allows you to specify a starting value and a maximum value for virtual machine memory allocation. For more information on Dynamic Memory Microsoft provides a technical whitepaper called: Implementing and Configuring Dynamic Memory.
RemoteFX will become a feature of Remote Desktop Services (RDS) which contains protocol enhancements and enables a rich graphics experience using server-side graphics processing by using a vendor supported video display adapter that supports specific 3D hardware acceleration. RemoteFX also provides USB support enabling remote users to redirect local USB devices to their remote desktop sessions. For more information on RemoteFX Microsoft provides a technical whitepaper called: Delivering Business Value with Remote Desktop Services.
Besides these 2 major enhancements the Service Pack will also contain bug fixes and other enhancements. In order to evaluate all of the new features Microsoft made available the Windows Server 2008 R2 SP1 Reviewers Guide.