The initial iPad offered customers Wi-Fi Internet connectivity, and the new iPad 3G provides access via AT&T's data network. IFixit tore open the 3G model over the weekend and revealed that device boasts 5 antennas.
The new iPad boasts five antennas in all, two for cell reception, two for Wi-Fi/Bluetooth connectivity and one more for GPS. In fact, iFixit says Apple is using the whole LCD frame as an antenna.
Other insights from iFixit iare that Apple used the same baseband processor from Infineon for both iPad models, but that the iPad 3G has a Broadcom BCM4750UBG Single-Chip AGPS, whereas the iPhone 3GS uses an Infineon Hammerhead II. IFixit even details what kind of screws are used to hold the iPad together.
Check out the iPad 3G Teardown on iFixit.com