In android, at least on my phone, dedicated camera buttons will take you to the camera application whenever you press them. It is quite nice, honestly I never bothered figuring out how to take a picture with it otherwise. In iOS I assume the UI is sufficiently less dreadful that this is not as necessary.

Not that this is a real solution, but you can lock and swipe up. Two motions instead of one.

No, I mean't like Windows Phone, the camera button takes a picture automatically regardless of the app your in.

There is no phone which has everything you need. Everyone has different aspects of things. Maybe the iPhone doesn't fit you. Why don't you buy an WP7/8 if it has those features?

I don't understand what this discussing is helping. It doesn't have one and I'm pretty sure it will never have a dedicated button. I can understand why Apple is not going the way others are going. This is a phone not a dedicated camera, so why would you mix these things? I know the camera these days are pretty good and a lot of people are using only their phones to point-and-shot but I think it would and it is (on different phones) feels wrong to have dedicated button for camera.

This is all my opinion. Others do different views but this mine. I respect every other view.