According to Apple, it's "engineered for maximum funness." iFixit, the repair site that regularly sacrifices new electronic devices to the goal of helping those who repair them, wanted to get inside the new iPod touch "to see just how much 'funner' the new generation is compared to the older generations." With heat gun and spudger in hand, they carefully disassembled a new blue iPod touch.
One cool thing they discovered right off the bat was that there's a little button to push on the back of the new touch. It's a retractable post for the color-