The choice of colors and gradients look terrible. They made iOS look worse. They swung too far away from skeuomorphic design. Even the art on the icons, without considering the colors, look like an amateur drew them. Look at the SDK icon: http://i.imgur.com/JXw7KQA.png That is ugly. So is the iTunes icon, so is the Safari icon. Not a fan.
They tried to get away from skeuomorphism, but still some remains. Just look at PassBook or the ugly 3D browsing through tabs. The whole design simply is not well thought out. This has clearly been rushed, which is not something I expect from Apple. If iOS 7 was leaked, people wouldn't believe it's the real thing. Sadly, it is. I'm staying with Windows Phone.
The new iOS looks half-baked, they can't do anything too bold, else they lose their metaphors, yet they can't do anything radical like Microsoft did without redefining their platform and re-educating their users.
Run away. Fast.