According to 9to5Mac and based on “reliable” sources, apple is expected to publicly release iOS 7.1 sometime in March.
iOS 7.1 will include everything from visual tweaks to bug fixes to some improved features, some user-interface tweaks in the Phone app, an improved Calendar app, speed improvements, and bug-fixes.
Here are some screenshots of the changes throughout the betas so far.
Slide to unlock & Phone
Circular icons

Dialer

Music
The Music app has more prominent Shuffle and Repeat buttons.

Keyboard
Keyboard has gone bold

Wallpaper motion
Apple has provided an option to turn off parallax completely in iOS 7.1. When switching to a new background, you’ll see a toggle to turn motion on or off..
Natural-sounding Siri voices
English Siri in the UK and Australia have been improved, as well as Japanese and Mandarin.
Screenshots courtesy of pocket-lint.com