With iOS 7 Beta 3 up and working for developers, it didn't mention any significant feature changes. However, early reports still indicate some UI tweaks, specially when it comes to fonts and icons within apps.
The first thing to be mentioned is that from the very moment of loading, iOS 7 is different - there is no linen that infused iOS 5 and iOS 6, but white and thin sans serif typography instead.
As a part of significant visual changes included in iOS7, the helvetica Neue Ultra Light has been introduced for apps, menus, and labels by Apple, but for all of two beta versions. Now citing the poor rendering on non-Retina displays, the design team has decided to eliminate visibility difficulties by beefing things up and moving from the Light version of the typeface to its regular weight in beta 3.
With this alteration almost going unnoticed, it l shifts away from the core visual blueprint of the initial iOS 7. Check the images provided below for more clear explanation and do not hesitate to express your opinion on how the change looks in the comments.