Before I’ll answer that (or better provide a link to to the official webpage of Microsoft about that topic) I want to tell that it looks like that SP1 for System Center 2012 will be general available from the 3rd of January 2013. So just a few more weeks to go before the bits can be downloaded. Nice!
The official webpage all about SP1 for System Center 2012 can be found here. As you can see there are many improvements. And because the webpage is a bit dated it might be expected there will more to tell about SP1 when it becomes GA.