Apple is planning to release iOS 6.1.2 early next week to address both the Exchange bug and lock screen passcode issue affecting iOS 6.1 users From MacRumors:

According to the report, iOS 6.1.2 is likely to arrive before Wednesday, February 20. Like iOS 6.1.1 released for the iPhone 4S earlier this week, iOS 6.1.2 will be a limited update addressing only these issues in order to allow Apple to quickly release it to the public.

 iOS 6.1.2 to Address Exchange and Passcode Bugs Reportedly Coming Early Next Week