I tend to think not. Sure, Apple has had quite the time trying to defend iPhone 4 and its supposed problems such as the death grip and gorilla glass scratching issues. The death grip problem turned out to be present on basically every cell phone ever made, and the scratching issue? Come on, if you want your stuff to stay nice, you have to play nice. But for the sake of debate, lets look at both sides of this rumor.
If we assume it to be true, then this would make the iPhone 5 look stunningly like an iPod touch, and thus similar to iPad 2. Apple also loves metal, so the design would fit in with the pattern of things.