Good question. If I was still the complete anime noob I was when I first started watching Naruto and I was introduced to Shippuden instead, I think I would at least give it a try in the hopes of seeing the scene that opened episode 1. But I don't think I would have stuck it out this long since it took them 27 episodes to offer even a hint that that scene might be coming up (a hint that you'd have to have seen the original to even pick up). Even as I am now, I don't think Shippuuden would have kept me watching this long if I didn't already know what was going to happen and when it was going to happen (or at least when I thought it would happen, since they seem intent on pushing things back as much as they possibly can).