We've already covered why legal iPhone unlocking and jailbreaking doesn't really matter that much, but Apple has chimed in with an official statement as well:
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.
Looks like nothing has really changed for iPhone users as you're still risking your warranty. [Cult of Mac]