When asked whether Sprint would eventually have no other option but to switch to tiered data plans if heavy users begin to come over in droves, Hesse replied that having enough bandwidth to efficiently go around "could be an issue," and while it's working diligently with OEMs and app developers in order to implement things like WiFi offload, we were told that "nothing is guaranteed forever." We specifically asked if the recent tiered testing implemented at Virgin Mobile (which runs on Sprint's network) was an early indication that Sprint was also leaning this way, and Dan was steadfast in his denial. According to him, the postpaid and prepaid sectors are markedly different beasts, and it's not reasonable to consider that Sprint will follow Virgin's footsteps. Moral of the story? Sprint's clinging to unlimited for as long as it can, but we get the impression that a transition is imminent -- even if it's still a few years out.