The standard answer I see most often is this; if you're upgrade date falls within the year, they will usually allow you to upgrade. Since your upgrade date is in 2012, you may have a difficult time obtaining a new subsidized iPhone. But it is not impossible!
Early upgrade policies seem to vary a bit, depending on the provider. Also, each customer service rep you speak with seems to have a different take on the matter. I've had the worst luck with the employees in the retail stores. For some reason, they all seem to stick to the date listed on your file, and will not even discuss an early upgrade with you.
Prior to making the jump to AT&T, I was with Verizon. When the Blackberry Storm was announced, I wanted to get one on launch day, but my upgrade date was a month and a half past the launch date. I tried several different Verizon stores in town, and each of them told me that employees in Verizon stores cannot allow early upgrades, and that I would have to call customer service. When contacting customer service, I spoke with several different reps, and all but one refused an early upgrade, even after I repeatedly "threatened" to switch to another provider if I was refused an early upgrade.
Frustrated, I began looking for a new outlet to voice my displeasure with Verizon. I stumpled across
www.planetfeedback.com, a site that allows you to file complaints with various companies, have that complaint forwarded to the proper person at that company, as well as post follow up comments showing how (or even if) that company responded to your concerns. I composed a short letter, telling Verizon that I was a loyal customer, and had been for quite a few years, and I felt like I was getting shafted on this deal.
The down side about planetfeedback is that other users can also comment on your complaints, and I was flooded with more than a few of the typical "Hey, YOU agreed to the terms of the contract. YOU signed your name stating that you agreed to a full 2 year contract prior to having Verizon pay for you to get a new phone" comments from other users. And honestly, they were right. By attempting to weasel my way into an early upgrade, I was trying to void the terms of my contract. I wasn't entitled to anything more than what I agreed to when I last upgraded my phone and signed on to ride the big red bus for another 2 years.
Verizon does however, have several customer service reps who are dedicated full time, to handling complaints through planetfeedback. At the time I sent my complaint, planetfeedback had Verizon listed as the top 2nd or 3rd company who follows up with concerns received. Shortly after sending off my complaint, I was sent an email from a Verizon rep, asking if it would be okay for her to contact me. I replied "yes", and 5 minutes later my cell rang. The rep was very polite, and apologized for the fact that I was not able to upgrade early while in the store earlier. She offered me an early upgrade, and even offered to have the phone delivered to my doorstep on launch day. I got my new BB Storm, and for a week or so, was convinced that I had something even better than an iPhone. 6 months later, I paid my ETF to Verizon, and picked myself up a new 3GS. I also felt that I kind of came off like a jerk, for badmouthing a company for not agreeing to terms that weren't in my contract to begin with.