Well this is what happened to me. I bought the iphone4 day one. my contract ends 2/2012 Go figure.
I can't get a new 4s because APPLE won't allow any changes to how the phone is sold. And I would have to pay the full price plus another 2-year contract. I tried:
1) Saying if I could just get my 2-year extended on the 4s by the extra 4 months. Nope. Can't extend because APPLE said no.
2) Can I order the 4s as a new line, and move my sim into it and cancel the new number? Nope. I would be charged for the 4s as it was activated with that new number.
3) Can I cancel my contract and pay my left over subsidy and get the new phone and put my phone number to it? NOPE. They would TOSS my number away and no garantee I can get the number back. Why? I cancelled contract, which means to them I no longer want my number.
4) So the only way is to port out my number to Sprint, get charged the subsidy left over and now I can get it for the $399+ Sprints 2-year? YUP.
It irks me to no end that to get a "wanted" phone early, I would need to pay $250 MORE, get another 2-year contract, AND still pay the same rates, not lower rates because I paid the $250 subsidy price.