Yesterday, iPhone jailbreaking was made legal by a new DMCA exception ruling. Apple [AAPL] has now made an official response about the ruling and essentially say that your warranty will be void if doing it.
‘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.