Step 7
The top of the logic board.
You can see the five button sensors, Apple logo ARM chip, and data ribbon cable (this leads to the headphone / dock jack on the other side)
The ARM chip has the numbers: 337S3300 844A N05WDK01 0642 ARM.
There's a smaller chip to the left of the Apple logo chip that simply says 'AAC.'
Step 8
The bottom of the logic board.
Apple has done an impressive job of packing functionality into the headphone jack. The dock plug has three conductive strips, plus the ground post. It's safe to assume that the plug is multi-modal and switches between USB, analog audio, and possibly power modes. The separate power mode may not be necessary if they can get enough juice off a 4 conductor USB connection.
It should be easy for a third-party developer to make a small USB adapter that restores the memory-stick functionality of the Shuffle.
Step 9
Battery flipped out
Notable features: Li-ion polymer battery (this is soldered onto the logic board), headphone / dock / power jack, and memory chip (hidden beneath the headphone jack.