The latest version of iOS software, which is currently in testing, apparently patches the exploits that are used by the Evasi0n jailbreak, meaning that the new software will prevent the jailbreak being used (via Forbes). The new beta 2 version of iOS 6.1.3, which was released for developer testing by Apple last week, apparently patches one of the five bugs that the Evasi0n jailbreak uses in order to allow access to the root file system of iOS devices, according to evad3rs team member @planetbeing aka David Wang.
While there are a number of other vulnerabilities that can be used by jailbreak software in order to jailbreak an iOS device, evad3rs are looking to see whether the latest version of iOS 6 patches any of the other holes. If it does, then it is likely that evasi0n would no longer be effective should users update to the latest iOS release, when iOS 6.1.3 is offered to the public.
Evad3rs will apparently carry on close examination of iOS 6 in order to look for further bugs that can be used in future jailbreak releases, and suggest that it may take around a month before iOS 6.1.3 is released and Evasi0n ceases working.