About the same, 8MP but improved quality.
If we get something near the Lumia 920 I'd be happy.
I wouldn't be surprised to see Apple make some pretty substantial improvements, the camera has featured heavily in the last 3 iPhone keynotes.
3GS - Video recording (possibly some other things were demoed, can't remember off the top of my head)
4 - 5MP lens, LED flash and 720P, front facing FaceTime camera
4S - 8MP lens, custom optics, face detection, 1080p and image stabilisation.
The 3GS camera upgrade was huge. The 3G's camera was so bad its laughable. See below the improvements. I think its safe to say we'll see another marked improvement on a similar level.
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