Today, Apple released BETA 3 of their iOS 7.1 software. This comes with many, many UI changes. Here are some:
First off, the key type on the keyboard is more bold than before, also the backspace and shift key have a grey color to them.
Another obvious change is the green gradient on the phone, messages, and facetime app. The green gradient on the bottom starts off darker than before.
iOS 7 has also been changed withing the phone app to fit closer with the already implemented buttons. Featuring circular call and call end buttons instead of rounded rectangles.
The phone power off slider also features a circle instead of the rounded rect.
It seems like iOS 7.1 will be about cleaning up UI changes that were missed during the official release of iOS7.