While the photo is lacking in detail, designer Surenix reproduced the fuzzy icons and created the following mockup which provides a peek at what Apple's new, flatter app icons could look like in iOS 7:
Here are the same icons in iOS 6, for comparison:
Right off the bat a more consistent design sensibility is evident in the iOS 7 icons. They're more unified and look like they came from the same design team. Most notably, the white borders and gloss effect found in the iOS 6 app icons are gone. Also missing are the faint diagonal stripes from the Messages and Phone app icons. The gradient backgrounds appear to have been completely removed from the Messages and Phone app icons yet curiously, they're preserved in the Music and Safari app icons.
The camera lens and gear wheel are slightly larger in the Camera and Settings app icons and the music note was changed from a dark red to white, which better matches the Messages and Phone app icons. iDownloadBlog also notes that Jony Ive appears to have added a touch of reality to the iOS 7 Weather app by adding clouds to its updated icon. If the leaked photo is indeed real, Ive also ditched the "73 degree" text from the old Weather app icon.
After the departure of Scott Forstall in October 2012, Senior Vice President of Industrial Design Jony Ive was promoted to head Apple's new Human Interface group. Ive has been rumored to minimize the use of skeuomorphism in Apple’s iOS in favor of a flatter design. If real, the leaked image of the iOS 7 home screen would appear to bear that out.
iOS 7 is widely believed to be announcemed at Apple's annual developer conference, WWDC, which opens on June 10, in San Francisco.