Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
Phil Schiller Defends App Store Approval Process
"We've built a store for the most part that people can trust," he says. "You and your family and friends can download applications from the store, and for the most part they do what you'd expect, and they get onto your phone, and you get billed appropriately, and it all just works."
Schiller goes on break down the major types of rejections. He explains that 90% of rejections are due to technical errors or bugs while 10% of rejections are due to inappropriate or illegal content. Meanwhile <1% of app rejections fall into a legal gray area that require additional research before they can make a decision. One example of such an application was one that teaches you how to cheat at gambling in casinos (in this case, it was rejected).
The source of frustration for developers have frequently come from inconsistent review standards and vague communications from Apple. Apple has been making some efforts to improve the transparency of the approval process, but obviously not enough yet to fully appease many developers.