That's what I've been thinking too. If it's really thin, as in less than 7mm, it could make up for the tallness. But on the other hand, most would prefer a large battery. I do hope Apple will surprise us, but I just think this will be it.
I will try to make a 5.5" iPhone too
I just don't see an asymmetrical iPhone happen, even though it would make more sense footprint wise. The Sharp Aquos Mini is a good example of what you could do without a top bezel.
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You only need to get used to it
They propagated one-handed usage on a phone 6 years ago. A 4.7" or 5.5" device is something that most people see as an internet communications device instead of a traditional phone. The mobile world has changed a lot and so have peoples needs. Many use their phone or phablet to read, mail, browse, message, game, etc and using two hands is almost more common than one hand. I think that iOS8 will see more gestures to make one-handend use more easy on a larger screened device.