The Galaxy S6's rear 16MP camera is on par with the iPhone 6's rear camera and we actually like its front-facing camera a lot more than the iPhone's FaceTime camera.
While we might not see a dramatic overhaul to the iOS camera app in iOS 9, we could see Apple make some big changes to the iPhones camera sensor. Rumors point to the arrival of a 12MP camera sensor (with 4K support) in the rear and a 5MP camera in the front.
Megapixels don't mean everything but this would be a huge move. The iPhone's been using an 8MP camera sensor for many years now and a switch to 12MP could be huge for the iPhone.
It's also worth mentioning Samsung's outstanding camera application that offers tons of modes for every situation. Apple's camera app is getting better but it still doesn't offer as much choice as Samsung's software. Apple might have some iOS 9 tricks up its sleeve though, especially if it's making these major upgrades.