Apple’s official response (as reported by Cult of Mac) in regards to the Librarian of Congress’s recent DMCA exemptions:
Apple’s goal has always been to insure that our customers have a great experience with their iPhone and we know that jailbreaking can severely degrade the experience. As we’ve said before, the vast majority of customers do not jailbreak their iPhones as this can violate the warranty and can cause the iPhone to become unstable and not work reliably.
There isn’t really much else they could do about it. Future iOS software updates will undeniably continue to break compatibility with jailbreak software. There likely won’t be any real effect on the jailbreak community at all — people will still jailbreak their devices and Apple will continue to plug holes in iOS to try and block jailbreakers.