It received quite a few negative opinions over the internet, mostly related to software and reliability, but inside it is astonishing piece of hardware. Most visible thing would be light but solid case made of AZ91D magnesium alloy (metal surface visible after scratching):
Altera EPM7064AETC100-10, 3.3V EEPROM-based CPLD, ISP via JTAG, 1250 gates, 64 macrocells, working as ATA glue logic circuit
D741649 - TIC hard disk controller
TEA5880 FM tuner
FM tuner (apart from well-known Altera PLD) is worth mentioning. This IC requires only two external components - two coils (top side) that can be also replaced with PCB traces. Coils on the bottom side just filter VCCA and VCCD. It doesn't even require external crystal (the price for this is software calibration requirement). Major drawback seems to be power consumption - according to datasheet 250 mA (typical) to 500 mA (max) from VCCD. That would give 2.5 W power dissipation at VCCD = 5V! Not sure if this is not just print error as it would consume HDD070 battery in 2 or 3 hours.
Micron 48LC16M16A2 256-Mbit SDRAM arranged as 4 Mbits x 16 x 4 banks with a
CAS latency of 2 at 100 MHz (see: Using SDRAM on AT91SAM7SE Microcontrollers Atmel Application Note).
Big up and down switches are Panasonic EVQPWBA15 with double-action (to get the idea: one of their recommended application is shutter switch for still camera).
Keypad and headphone remote are using trick with resistance switching - more that one key can be handled by single ADC input.
PCF50605HN, power supply controller - real monster: 3 x DC/DC switching converter, 5 x linear regulator, battery charger and a lot more; produces 1.8V (ARM core), 2.4V (Flash), 3V (wake-up, CPLD, tuner), 3.3V (HDD) and 5V (LCD backlight).
Power supply section - 3 "double-C" shaped inductors visible with thick wire.
Display with integrated controller; 128x96, 2 bit greyscale.
CORNICE 2GB model 200LMTLF543 hard disk drive.
Philips HDD050, HDD055, HDD065 and HDD075 seem very similar to this player - main difference is used hard disk capacity and RAM buffer memory size.
Best of all: schematic is pretty easy to find.