Well, to be fair you can't "redesign" something that does not exist, so I doubt we'll be seeing a redesigned iPhone 5 😉
Do I think we'll be seeing a phone called iPhone 5 that has a different design to the iPhone 4/4S? Quite likely given how long it has been since the iPhone 4 launched and how much the competition have moved on since in terms of physical design. I know it's not all about the specs, but there comes a time when a certain standard is expected just because the baseline has moved.