According to some anonymous sources of 9to5Mac, iOS 7 is going to be the biggest change to Apple's mobile OS yet, where we should expect it to be: a flattened, minimalistic, anti-skeuomorphic UI poured uniformly atop its next-gen mobile OS.
Jony Ive is the man responsible for this big change, with his design chops resulting in what we have with the iPhone, iPod, iPhone, iPad, iMacs and MacBooks. Both Ive and Jobs were very close, where Jobs' biographer, Walter Isaacson labeling the two men as "soul mates". There have been teases of iOS 7 in the past, but we haven't heard about the black and white aspect of it yet, which would be a huge jump.
9to5Mac's sources claim that iOS 7's home screen icons will ditch their shadows and gloss, replacing it with flatness. The icons to Game Center and Note will lose their older-themed look (such as green felt, leather-like trim, etc) and in replacement, we'll have solid color and style. We shouldn't have to wait long for iOS 7, which should be unveiled at WWDC.