Microsoft show Service Pack 1 for Windows 7 and Windows Server 2008 R2.
What's new ? Nothing special ...
Server 2008 - " Dynamic Memory lets Hyper-V administrators pool available memory on a physical host and dynamically distribute it to any virtual machine(s) running on that host, while RemoteFX lets Windows Server 2008 R2 administrators provide a rich end user desktop virtualization experience by delivering vivid content, independent of any graphics stack, to server-hosted virtual and session-based desktops"
you can downlaod it from Windows 7 update or from official Microsoft website.