The United States Library of Congress has added anti-circumvention exceptions to the Digital Millennium Copyright Act that now states that jailbreaking is not a violation of copyright law - Apple's main argument against jailbreaking.
Some of the cost compelling quotes from the 250-page recommendation:
Ultimately, Apple’s position with respect to harm to the market for and value of its firmware boils down to Apple’s conclusion that “the value of the iPhone, and hence the software embedded in it, is substantially diminished when the integrity and functionality of that software is compromised by jailbreaking, when Apple is left to deal with the problems that ensue, and when the positive feedback loops enabled by the App Store and the iPhone Developer Program are compromised.”
Apple’s objections to the installation and use of “unapproved” applications appears to have nothing to do with its interests as the owner of copyrights in the computer programs embodied in the iPhone, and running the unapproved applications has no adverse effect on those interests. Rather, its objections relate to its interests as a manufacturer and distributor of a device, the iPhone.The recommendation does not only apply to Apple devices. Android powered phones, like the Driod and HTC phones, can also be jailbroken (A.K.A. rooted).
Though this does not mean that Apple will stop jailbreakers by issuing updates for holes in software.
The Electronic Frontier Foundation, the largest group fighting for a "free" electronic world, estimates that there are about 1 million jailbroken iDevices. This number will likely only continue to increase because of this recommendation.