Just got my hands on iPad 2 today.
Quick Teardown on iFixit.com
iPad 1 3G – http://www.ifixit.com/Teardown/iPad-3G-Teardown/2374/1
iPad 2 3G – http://www.ifixit.com/Teardown/iPad-2-3G-GSM-CDMA-Teardown/5127/1
Notice that iPad 2 is using Broadcom BCM4751 Integrated Monolithic GPS Receiver, while iPad 1 and iPhone 4 is using Broadcom A-GPS BCM47501UBG
