Apple's iOS developer site says that iOS 6.1.3 beta 2 was released on Feb. 21. That means the new version could be released at any time.
When evasi0n was released, the evad3rs dev team said that they used multiple exploits -- five bugs in the OS -- in order to create the jailbreak. According to one evasi0n’s creators, David Wang, who tested the upgrade over the weekend, the 6.1.3 beta 2 patches at least one of the exploits, which will end the efficacy of evasi0n to jailbreak devices after they are upgraded to 6.1.3.
Naturally, hackers such as the iPhone Dev Team and the evad3rs will tell folks that when iOS 6.1.2 comes in they should hold back on upgrading. It's unclear how long a new jailbreak will take, but the evad3rs said, when they released the hack, that they had backup exploits ready in case Apple patched this jailbreak.
Wang also added that he is continuing to test the patch to determine if any of the remaining four holes have been closed by Apple. He said,
If one of the vulnerabilities doesn’t work, evasi0n doesn’t work. We could replace that part with a different vulnerability, but [Apple] will probably fix most if not all of the bugs we’ve used when 6.1.3 comes out.When evasi0n was released earlier this month, it quickly became the most popular jailbreak in history. Nearly seven million iOS devices were jailbroken in the first four days of its release.
Jailbreaking is similar to rooting on Android. It allow the installation of software that Apple would otherwise disallow -- software not in the App Store. The first iPhone capable of background processing was a jailbroken iPhone.
Some say that the most useful smartphone is a jailbroken iPhone, though naturally owners of rooted Android phones might disagree.
This would be the third post-iOS 6.1 fix that Apple has pushed out very rapidly since the release of iOS 6.1. iOS 6.1.1 was released to fix a 3G connectivity bug on iPhone 4S devices, and about a week later iOS 6.1.2 was released to fix an excessive logging issue on Exchange servers.