If you’re looking for a quick way to describe the shifts involved in the transition to the Common Core Standards, consider the “Common Core Shifts” entry here. There’s a wallet-sized version and a one-page version for each of math and ELA/Literacy. Actually the whole Achieve the Core site is worth perusing, not just the “Steal These Tools” page.
While we’re on the subject of sanctioned stealing, a.k.a. open-source materials, am I naively idealistic to think that we ought to be sharing more rather than less if we’re going to improve mathematics education? There are websites (to which I won’t link, but they’re not hard to find) where you can pay to download another teacher’s lesson plan, on the theory that the teacher put a lot of time into the plan and should be compensated. I’m uncomfortable with this, in part because that teacher is building on other people’s ideas, and besides, doesn’t the teacher already get a salary for, in part, developing lesson plans? More fundamentally, though, the pay wall makes it less likely that you will compare and contrast several plans for the same lesson and choose the best, which you might then make even better and share with the crowd. In contrast, it’s fascinating to watch the Illustrative Mathematics website evolve. This diagram illustrates the open-source process nicely; don’t skip the caption.