I spoke to Apple support about this, and from what the rep told me - I can't sign up for the Upgrade Program on the same phone I'm returning because I would be given a new phone. He was being cautious in his wording, and I don't blame him, but my original plan was to open up the box, play around with the phone, and then return / rebuy under the iUP if I ended up liking it at my own time. I'm having second thoughts on what my course of action should be now. Since I'm with T-Mobile, going in-stores to sign up for the program (since it's mandatory) on launch day (assuming I get that lucky) isn't something I'm looking forward to, assuming there will be a crowd. On the other hand, I'm wondering if it would be possible to sign up if I haven't opened the shipping box / iPhone box. Has anyone done the latter before?