When Microsoft first released Service Pack 1 for System Center 2012, there was a short period of pain when early adopters found that it was broken due to it shipping with a certificate that expired almost immediately. Thankfully that was quickly resolved and what is available now is an excellent update in terms of support for new versions of Windows and enhanced functionality.
I would recommend that people look at Microsoft Virtual Academy for details on the updates in SP1. They actually have two courses that cover it: System Center 2012 SP1 Updates and System Center 2012 SP1 Capabilities.
As usual, Microsoft has evaluation versions of the software available and you can grab System Center 2012 SP1 (handily with or without System Center 2012 in the same download bundle) from this link.