From the Verge:

During the D11 conference this evening, Apple CEO Tim Cook was pressed on the fact that Apple’s software is more closed in comparison to other platforms such as Android, and admitted that the company could be softening on that stance — to a degree. “On the general topic of opening up APIs, I think you’ll see us open up more in the future,” he said, “but not to the degree that we put the customer at risk of having a bad experience. So there’s always a fine line to walk there, or maybe not so fine.”

I think a lot of people fail to understand how difficult this line is to walk. Many will say (I included) that Apple needs to open up iOS more if they want to compete with Andoid, but many more will complain if the experience suffers because of it. Don’t underestimate how much the 10s of millions of iOS users expect their devices to “just work.”