Apple has released iOS 9.1, a small update for iOS 9 that at long last brings the taco emoji to the iPhone. The update includes a number of new emoji, including a burrito and hot dog, several more smiley faces, places of worship, and sports equipment. There's also a unicorn!
This should make Live Photos work much better
Depending on your perspective, the other change in this update is the more/less interesting one: Apple is tweaking how Live Photos work to make them turn out a lot better. The iPhone 6S will capture 1.5 seconds of footage before and after a photos is taken to create a Live Photo, but that back 1.5 seconds is often just the iPhone being put away in someone's pocket. Now, the camera will stop recording if it detects that the iPhone is being lowered. So Live Photos should be a lot nicer.
The update also includes stability improvements to CarPlay, better performance in the app switcher, and various bug fixes. Apple is also updating OS X today with support for all of the new emoji, plus more/less important things like better compatibility with Microsoft Office 2016.