In my opinion, iOS 7 introduces a completely new design that's only half baked.
Many people seem to agree that the icons are a misstep. I feel like that they exhibit neither beauty nor coherency. Some icons have gradients (messages, weather, camera) or shadows (settings), others only a white background (photos, game center), some have a very textured and bubbly look (game center again), while other exhibit more design elements of what has been lately referred to as "flat design" (stocks, compass, newsstand). I personally find the latter the most well-designed and pleasing to the eye.
The same applies to the general impression of the apps themselves, where I would have been happier to see a more coherent design. I really like the design of the weather, clock, calculator and compass app, but find these to be in stark contrast to other apps (newsstand, game center, camera) as far as the visual style is concerned
That being said, it makes me hopeful that some of the places where iOS 7 falters design-wise may simply be due to the tight deadline for WWDC, as one author
points out, and may see improvement in the GM or future iterations.