Microsoft has released a few details about the upcomming service pack for Windows 7 and Server 2008 R2. One of the more interesting new features is support for 3D acceleration support over RDP allowing users to play silverlight movies, use Aero or more importantly heavy graphics based apps like CAD that use 3D.

Windows Virtualization Team Blog : Explaining Microsoft RemoteFX

This experience includes full-fidelity video with 100% coverage for all media types and highly-synchronized audio, rich media support including Silverlight and 3D graphics, and of course Windows Aero.
With Microsoft RemoteFX, users will be able to work remotely in a Windows Aero desktop environment, watch full-motion video, enjoy Silverlight animations, and run 3D applications – all with the fidelity of a local-like performance when connecting over the LAN.
They are also teaming with Citrix to add this feature into their offering too. According to the posting it supports OpenGL also meaning it will work with the heavier CAD apps and Windows 7 will be supported as a VDI host under Hyper-V. I hope this means I'll be able to use this from my media center to laptop remotely as well.

Other than that SP1 does not yet have an official release date but W7 and 2k8R2 versions will be released at the same time and are reported to be mostly minor bug fixes rather than feature packs as SP2 usually is.