The majority of the System Center 2012 suite of apps have been available in downloadable VHD format for a while. Published on August 20, 2013, the VHD for Configuration Manager 2012 SP1 is now available and completes the list.
VHDs are used to create virtual machines for testing products. VHDs are one of Microsoft's suggested ways for replacing the download options revoked through the retirement of TechNet subscriptions which has many in the IT community up-in-arms about.
You can grab the ConfigMgr 2012 SP1 VHD here: System Center 2012 Service Pack 1 Configuration Manager – Evaluation (VHD)