You seem to be saying that all models of iPad, including the WiFi-only versions, have a GPS satellite chip in them. Can you confirm that this is true? If I get one, this fact will greatly affect which model I select.
That was my mistake, I should have distinguished between the iPad's but got carried away going into the details.
As others have said, only iPad 3G's have "real" satellite based GPS. I edited the post to reflect that.