The Story: Apple put out a press release Monday saying that the latest iPhone firmware, to be released this week, may permanently disable iPhones that were unlocked to be used on other carriers.
The Definition: "Unlocking" the iPhone allows it to be used on any GSM phone carrier by switching the SIM card. This is different than "hacking" or "jailbreaking" the iPhone, which allows you to install third-party applications. Apple's warning Monday was about unlocking, not hacking.
The Backlash: Customers freak. Rightfully so, since unlocking phones is not illegal nor a violation of the DMCA.
The Backpedal: Apple vice president Phil Schiller claims that some of the iPhone unlocks have "caused damage to the iPhone software," so no promises can be made to the continued operation of unlocked phones with the updated firmware. He says it has "nothing to do with proactively disabling a phone that is unlocked". * [NYTimes]
The Response:: Hackers remind iPhone users that they can still download and save the current, working firmware version, while questioning what software, exactly, might have been damaged by unlocking the SIM. [Hackint0sh]
The Optimist's Outlook: Some part of the unlocking process overwrote part of the iPhone's memory in such a way that Apple is unable to update the firmware without guaranteeing interoperability.
The Pessimist's Outlook: Apple, having already entwined itself with sanctioned carriers, is making the decision in an effort to protect its bottom line, as Apple receives a cut of iPhone customers' monthly fees only if they are using an official carrier. See also: Apple's lack of an iPhone instant messaging application, forcing users to use SMS instead for an additional fee.
The Odds: 80/20 that Apple are being anti-customer bastards.
The Clincher: If hackers can unlock iPhones running the upcoming firmware, Apple is intentionally putting poisoned messages into the media to ward off those who might choose to do something that is perfectly legal.
* He also said "or hacked," but I think in context it's clear he's only talking about hacks that might unlock the phone for use on other carriers, not third-party applications.