It seems that Apple is taking on every bug one by one. This time they have released a new version of iOS 6.1.2 for all the Apple devices, not with an intention to save the jailbreak but to fix the Exchange bug which was responsible for the huge UI lag. Now if you have already ‘jailbreak’ your device then you will definitely want a turn-around for this issue rather than installing the new version of iOS on your iPhone again.
The solution to that problem is to delete than Exchange account from your iPhone and then reconfigure it again, this will definitely solve the issue. But if you feel that new iOS will be the best solution then you can install it and be assured that the tool downloaded from evasi0n will be able to jailbreak as it was done the previous time. You should also know that this new version of iOS warns the users of the problems related to be less battery life and more background network activity.
Well it is still expected that Apple will try to release the new version of iOS to prevent the jailbreak and luckily the team of evaD3rs are prepared for it. So, Apple has seeded iOS 6.1.3 to the developers and you can also expect to see that on your iPhone by next month. We will keep you updated with the new iOS versions if declared.