Based on the little I know about signal strength for digital phones, the number of bars really doesn't matter, The bars could just be replaced with an indicator letting you know whether or not you have strong enough signal to make a call. And from that perspective, the stats discussed today that there is less than one additional dropped call per 100 calls make this whole thing seem like a non-issue.

However, what I haven't heard discussed and would like to hear about from someone who knows what their talking about is whether or not signal strength affects data transfer rates. I use data a lot more than voice on my phone and if it's significantly easier to reduce the signal quality on the iPhone 4, I don't think I would get one.