Apple just released the huge update for iOS 7, fixing some things visually, adding some additional accessibility options, turning on CarPlay support, and squashing some bugs. Some unexpected additions are manually controlling Siri, a redesigned Calendar (I use Fantastical though), and automatically enabling the camera’s HDR mode on the 5S. The update is about 200MB-300MB and available through Software Update on the device (Settings > General > Software Update) or iTunes.
I’ve updated my iPhone 5 already and am mostly happy with the default changes—I would use Button Shapes if it had more of a dark outline than a grey blob behind my buttons. I actually think the biggest improvement is stability and responsiveness.