★ Icons on the iPhone home screen have received a slight increase in size up from 114px and 57px to 120 px and 60px respectively
★ A new golden ratio grid has been introduced. (but so far people, including apple, seem to be taking it very casually)
★ A very bright new color scheme is included in the PSD
★ New iOS 7 app store and home screen preview generators
★ More flat
★ A new curved outline… Oh the elusive corner radius.
more interesting infos (especially on the corner radius of the new icons) here Start making iOS 7 Icons with the App Icon Template 3.0 | Pixelresort.com.