Apple has officially released iOS 8.1.1. The update includes bug fixes and performance improvements for older hardware. This is good news for iPhone 4s and iPad 2 owners who were concerned about a previous Ars Technica report that said iOS 8 ran slower on these devices. iOS 8.1.1 also patches the recently released Pangu jailbreak and should be avoided if you plan to keep your device jailbroken.
At the time of this post Apple is still signing iOS 8.1. Meaning this is your last chance to upgrade to 8.1 if you want to jailbreak at the last iOS release possible. It is unknown when Apple will stop signing iOS 8.1, so upgrade now while you still can. You can learn how to jailbreak your device using Pangu on Mac OS X here or Windows here.