So you're saying that to remain ahead of the others, in terms of looks, they have to redesign every year? I guess that makes sense but if they keep redesigning so often, there's pretty much guaranteed to be another "antennagate" issue of some sort because of designs being rushed. Obviously, that could be prevented with thorough testing and such but I'm not sure if that's something they'd risk. I agree with you, though. I'm just trying to think what they might be thinking.
Not just looks but feature set. In order to add certain features the design may also be need to be altered. Besides they need to stay fresh. Using the same design just becomes stale and stagnant. That said I do like the iPhone 4 and would be happy if they kept it the same but add better functionality and features.