I don't know how their design people allowed a protruding lens in the first place. It really runs contrary to Apple's design sensibility, but I guess we're seeing the first evidence of what happens to Apple without Jobs. The protrusion is ugly, and it mars the flat, smooth design.
The 5th generation iPod Touch (most recent, I believe) has a protruding lens which sticks out about 1 mm also. That came out about 2 years ago, and I have one. The protrusion is just enough to be annoying if you don't use a case.