Now that iPad 2 is revealed, all the speculation shifts to iPhone 5. Here's an article from BGR suggesting that the iPhone 5 will ditch the trouble-prone antenna design & form factor of the iPhone 4 and go with something the looks a lot like the 4th gen iPod Touch. The new antenna would be integrated into the aluminum logo on the back (go figure hehe).
Man, I really don't like the rounded back they seem to be shifting to on all their devices. For some reason, it reminds me of the egg-shaped Ford Probe from the 90's hehe. I guess if it results in a better antenna, it's a good trade off.