Apple pushed out the update earlier than expected we were expecting this update to come out on Saturday. It fixes the SMS exploit and you will lose your jailbreak if you are jailbroken. Please do not update until the iPhone Dev-Team gives the OK if you want to keep your iPhone jailbroken. For those of you who do not care, you are free to update it iTunes. Now don’t get exploited by a SMS message waiting for the Dev Team to release their updated RedSn0w.
You can download the firmware here.