I have read lots of articles about the pros and cons of Common Core. The radio show linked below, shows both.
I think if the Common Core tests are used punitively in the schools, it could be a problem. This adds a layer of fear in the teaching of the standards. It makes it difficult to try these "new" ways of teaching when worried that making an error or allowing students to find the answers will lead to poor scores that will adversely affect a teacher's livelihood. Also, Common Core was not meant to keep the focus narrowed on math and reading. It was meant to allow arts, sciences, and social sciences to have equal footing with math and reading. We will see if this is the case.
Anyway, this is worth the listen:
http://www.americanradioworks.org/documentaries/greater-expectations/