Last minute changes to the RDP protocol in Windows 7
As Windows 7 RTM is closing in really fast the Microsoft Remote Desktop Services team (formerly Terminal Services team) has announced that there are some last minute changes to the RDP protocol and that some code that was in the Windows 7 pre-RTM build is left out from the RTM code. Specifically this is related to DirectX 10.1 applications and instead of rendering those apps on the client these are in the Windows 7 RTM builds (and Windows Server 2008 R2) rendered on the host.
Other new features in the Windows 7/Server 2008 R2 RDP protocol such as playing high definition videos in Media Player and it being rendered on the client is still there, along with other optimizations and tweaks are still there to provide a significantly better RDP experience than in previous versions of Windows.
Source: RDS blog, http://blogs.msdn.com/rds/archive/2009/06/19/changes-to-remoting-model-in-rdp-7.aspx