Easy Print Redirection was available for Windows Server 2008 TS only and it was not available when connecting to computers running Windows Vista. Now it will also be available when connecting to Ultimate/Enterprise editions of Windows 7 and Windows Server 2008 R2 Remote Desktop Session Host servers. In addition, we’re happy to announce that with Win7 / WS08 R2, Easy Print no longer has a dependency on .NET Framework -- a common request from customers that didn’t want to install .NET on all clients from which they wanted to print. The XPS format to GDI conversion was done via .NET Framework before, but for Win7 / WS08 R2 the operating system does this conversion itself.
Full Article: RDS blog