So the iPad-HD teardown.
-1GB of RAM. Two 512MB Elpida LP DDR2 packages are soldered on the logic board underneath the A5X processor
-Broadcom 802.11n-compatible Wi-Fi chip with Bluetooth 4.0 support as well as an FM transceiver, an Apple-branded power management IC, Toshiba-made NAND flash, and a Qualcomm MDM9600 baseband
-Samsung display "Retina" screen
- 42.5Whr battery (the iPad2 battery is 24.8Whr). This is needed to keep the same 10hr charge.
It's amazing how much tech you can cram into such a thin space these days.
http://arstechnica.com/apple/news/2012/03/ipad-3-teardown-my-god-its-full-of-lithium-ions.ars