Answer (from the IRA Common Core Standards Committee):
Reading comprehension certainly is given a lot of weight in the standards. Comprehension standards are the first ones reported and there are more comprehension standards than there are any others. Reading comprehension echoes across the writing, speaking and listening, and language standards, too. Phonological awareness, phonics, fluency, oral language, writing, vocabulary, and language conventions are all given extensive and appropriate attention, as well. It would be a mistake to decide that some outcomes are the important ones; they all are.
Common core comes from the "fewer, bigger, better" school of standards writing. Past standards have been extensive in number and unequal in grain size (with a mix of small items that could be learned quickly and big ones that could be worked on for years). That made it necessary for schools to try to prioritize the standards that could provide the biggest learning payoff; that approach won't work well with the common core standards.
That said, there do seem to be a few gaps in regard to comprehension. For example, the writers of the standards say that they decided not to discuss a full range of metacognitive strategies (things like activating prior knowledge, visualizing, and determining importance), that teachers would need to teach, but acknowledge that students will need to learn them. We are encouraged to use our professional judgment when teaching students to meet the standards. It's important to make sure our students get the literacy instruction they need.