Zune Chipset Information

• Main CPU Freescale MCIMX3 Arm 11:

link1 | link2

• PC To Video Chip Focus  FS456 :

link

• Audio Chip Wolfram WM8978:

link1 | link2

• Power Managment Freescale MC13783:

link1 | link2

• USB-OTG Philips  ISP1504A:

link1 | link2

• Flash 64MB RAM (4M x 32Bit x 4 Banks Mobile SDRAM) Samsung K4M51323PC:

link

• Flash 2 MBytes NOR, 3.3V, 1Mx16 Boot block (PH28F160C3TD):
  

link

• Wi-Fi KeyStream Corporation KS3021:

link1 | link2 (Japanese) | link2 (English Google Translation)

• FM Tuner: Silicon Labs Si4701 single-chip radio tuner (4701A15):

link

• Bus Switch: Low voltage octal FET bus switch (CL245 / SN74CBTLV3245A):

link

Here is also an excellent article describing Zune's chipset in detail:
http://happymac.ch/happyMacEN/News/1C1515C1-A47C-4ADD-8A16-9B3A21C9AA5A.html