Side A

 * (In Red) STMicroelectronics UIC-WUP MCE GH226
 * (In Orange) STMicroelectronics MSA3D 01F
 * (In Yellow) Texas Instruments TSC 2046I Low Voltage I/O Touch Screen Controller

Side B

 * (In Red) InvenSense ITG-3280 Gyroscope
 * (In Orange) Micron 25Q256A 256 Mb Serial Flash
 * (In Yellow) DRC-WUP 811309J31 1217LU603
 * (In Cyan) Texas Instruments AIC3012 Audio Converter
 * (In Blue) Texas Instruments 1010007

Pictures and information from: http://www.ifixit.com/Teardown/Nintendo+Wii+U+Teardown/11796/4

5GHz WiFi Module

Wii U GamePad 5GHz WiFi Module (Top)

Wii U GamePad 5GHz WiFi Module (Bottom)

NFC connectivity

Pokémon Rumble U

Pokémon Rumble U is the first Wii U game to make use of NFC connectivity. NFC figures are writable and store data for use in-game. No two figures are alike; each has unique stats and information in-game. For more information see Rumble U NFC Figures.

Amiibo

The marketing name for the NFC enabled figures. See: http://www.amiibo.com/ , http://www.nintendo.com/amiibo

Amiibo Figures

Available NFC enabled figures:

01 - Mario
02 - Peach
03 - Yoshi
04 - Donkey Kong
05 - Link
06 - Fox
07 - Samus
08 - Wii Fit Trainer
09 - Villager
10 - Pikachu
11 - Kirby
12 - Marth
13 - Zelda
14 - Diddy Kong
15 . Luigi
16 - Little Mac
17 - Pit
18 - Captain Falcon

Amiibo Supported Games

Super Mario Maker
Super Smash Bros. for WiiU
Mario Kart 8
Captain Toad Treasure Tracker
Mario Party 10
Yoshi's Woolly World

NFC module pinouts

NFC data from Pokémon Rumble U figures

For more details on Amiibo, see here.