I'm quite happy with the improvement in "from pocket to picture" time iOS 5 and the 4S brought. This is also an improvement I partially attribute to the competition in the mobile space. One of the priorities for Windows Phone 7 was this speed. They solved it by enforcing a dedicated camera button on every phone. If the device is asleep, even with a pin lock, pressing and holding the button caused the device to go into picture taking mode. The button also had the two stage action most point and shoot cameras have. This competition, along with user feedback likely helped to improve things for iOS users.

It's a fine line between copying another idea with the understanding of why it was a good idea, vs blindly copying everything, but not copying well enough to keep the spirit of the idea alive.