Unless specified in the contract otherwise, data plans tend to be grandfathered from phone to phone. Considering if the Thunderbolt is released with unlimited 4G, could this mean the one and only chance for a person to get unlimited 4G? If my warped premise is correct, it may be better to get the Thunderbolt in order to lock unlimited data in for 4G. This IMO would be a reason even for a dual core lurker like me to consider the TB. Future proof 4G data.... Yes, the premise IS a stretch, but perhaps plausible?