iOS 7.1 is expected to bring several changes across the board to the OS. A lot of them are UI changes, such as a new dialer, redesigned Slide to Unlock UI, redesigned Caps Lock and Backspace keys on keyboard, ability to remove parallax effect on wallpaper without disabling all motion effects, and a few other tweaks here and there.
Apple has also improved performance compared to the current 7.0.4. On the new iPads, for example, the latest beta is a lot smoother, to the point where it’s hard to tell which is the beta and which is the stable release. There are also going to be the usual bug fixes.
Hopefully, the update comes out soon as iOS 7 is in need of some fixing in its current version.