They advertise that all of the code is open source and with a less restrictive license like BSD so you can include it in your products. Here are the main libraries:
- Bluetooth stack (BSD license) with libraries for RFCOMM, A2DP,L2CAP, SDP
- Multimedia library including an ogg player
- MicroSD SD/SDHC driver with FAT12/RAT16/FAT32
- USB Host stack with Android open accessory protocol implementation
All of this runs on the Atmel SAM3X ARM Cortex-M3 processor with 512kB flash, 100kB RAM, and bluetooth is provide by a Texas Instruments CC2564. There are also sensors for light, proximity, acceleration, magnetism, temperature, humidity, barometric pressure, and other toys like a capacitive slider and buttons, RGB LEDs including the 7 segment display, a transducer speaker, and an NFC tag.
For more info, here is the developer's guide from google Accesory Development Kit 2012 Guide. A little more info about the Arduino IDE (for an ARM processor) it uses on the Arduino blog.
The surprise at the end of the video is that an ADK 2012 was given to each attendee of this talk, and the device is not for sale (yet). If you really want one, try e-bay, currently the best price is an auction at $400 US. If are lucky enough to have one here is the Android app from google play.