Earlier today, Apple released iOS 6.1.2 where shortly after, planetbeing confirmed evasi0n works on iOS 6.1.2 but we would need to wait for it to be updated. The evad3rs have officially updated evasi0n for Mac, Windows, and Linux to officially support the iOS 6.1.2 firmware.
Apple has just released iOS 6.1.2 to address some small issues. That doesn't mean that an update can't render a jailbreak useless. Fortunately planetbeing is reporting that evasi0n appears to still be working under iOS 6.1.2. Obviously, you'll still need to hold off on updating until evasi0n is updated to recognize iOS 6.1.2 as a supported firmware.