As an educator who has studied the math Common Core extensively and implemented it in my own classroom, I am excited about the opportunities it affords. This is not a "dumbing down" of the curriculum; rather, on every grade level, expectations have been thoughtfully increased.
However, instead of merely requiring more material to be covered, the Common Core addresses fewer concepts, but in much greater depth. Our core is no longer "a mile wide and an inch deep."
Coherence between the grades has also been carefully coordinated, so that each grade level builds solidly upon the previous one. The result will be students with a true grasp of math, instead of just memorizing techniques and formulas.