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-matched carrying "loop" that Apple includes with your iPod touch. After getting past the adhesive and clips that hold the display on, iFixit's team unscrewed an EMI shield to reveal the huge Li-ion battery inside.
At several points in the teardown, iFixit notes that "Apple is simplifying and grouping components in its products" and that this is "inadvertently putting an end to repairability." They give the iPod touch fifth Generation a repairability score of 3 out of 10, with 10 being the easiest to repair. The moral of the story? Get AppleCare for your products, since third-party repairs may be hard to come by and/or expensive.