Running the GPS on a phone eats up the battery, I wouldn't assume any phone company would be purposefully sabotaging the battery life of its own products to piss off its customers.
Some observations from a Pre owner. The GPS is on all the time by default (one reason for the Pre's reported poor battery life). When the GPS is off, it still can get a general idea where you are (this based on the fact when you open the Google Maps application it knows what city I'm in with a large circle indicating the "margin of error"). Turning the GPS off improves battery life significantly, so I deduce that the GPS receiver is really off.