Windows 7 SP1 wasn't anything special anyway (mostly Tuesday patches/fixes).
Dynamic Memory and RemoteFX are completely new in Service Pack 1. They were not released as a separate download ever. Both changed significant hardware stacks.
Remember, Service Packs are mostly for the corporate environment to make IT's life easier. They mostly only include the updates corporations require in their clients/servers.
From
Notable Changes in Windows 7 and Windows Server 2008 R2 Service Pack 1.doc.
WINDOWS SERVER 2008 R2:
-Dynamic memory for Hyper-V (allows the host machine to pool memory and send it to the virtual machine that needs it most)
-Microsoft RemoteFX (allows graphics-intense applications to be virtualized)
-Enhancements to scalability and high availability when using DirectAccess
-Support for Managed Service Accounts (MSAs) in secure branch office scenarios
-Support for increased volume of authentication traffic on domain controllers connected to high-latency networks
-Enhancements to Failover Clustering with Storage
WINDOWS 7:
-Additional support for communication with third-party federation services
-Improved HDMI audio device performance
-Corrected behavior when printing mixed-orientation XPS documents
BOTH:
-Change to behavior of “Restore previous folders at logon” functionality
-Enhanced support for additional identities in RRAS and IPsec
-Support for Advanced Vector Extensions (AVX)
-Improved Support for Advanced Format (512e) Storage Devices