The catch was, to install these third-party apps, users had to "jailbreak" their iPhones, which works by intercepting the communication that is supposed to happen between the iPhone and iTunes-- thereby voiding the warranty and running the risk that future iPhone software updates would render the phone inoperable. (emphasis Rastamon's)
Did the author even
read the iPhone's
warranty before writing this? As long as the hardware is not damaged, the iPhone's warranty is not voided.
From the warranty (emphasis mine):
…This Limited Warranty applies only to hardware products manufactured by or for Apple that can be identified by the “Apple” trademark…
This warranty does not apply: (a) to damage caused by use with non-Apple products…
Additionally, most states have implied warranties that must be honored by manufacturers. In other words, if Apple, or anyone else, sells a product advertised as a phone, the customer has a reasonable expectation for that product to function as a phone. Apple may well be within their legal rights to only allow the iPhone to function as a phone on AT&T's networks, but lacking any physical damage to the hardware, even an iPhone bricked from jailbreaking, third party software installs, etc; is still covered under Apple's warranty, regardless of what the local Apple Store's Genius™, Steve Jobs or AT&T claim.
Perhaps a bit of research is in order before
PC World Macworld spreads additional FUD regarding jailbreaking and the iPhone warranty.
Edited to correct misattribution of article's source.