You can still get the 2 year contract. Whether you save money on NEXT or not depends on the plan that you are on. If you are on the new Mobile Share Data Plans of 10gb or larger, it is cheaper in the long run to purchase using NEXT,
The Mobile Share Data Plans of 10GB or larger have a $25 per line discount for out of contract lines. When you figure in the cost of the phone upgrade, plus the $40 upgrade fee, plus the loss of the $25 per month discount for 24 months, it ends up costing about $100 more over 2 years for the subsidized phone.
With NEXT, you stay out of contract, keeping the $25 per month discount, and do not have to pay the upgrade fee of $40 and pay $0 out of pocket.
Do the math.
Now if you have a smaller data plan, depending on the cost of the phone, it may be cheaper to do the subsidized upgrade.
On the new plans, AT&T not longer subsidizes the phone costs. One way or another, you will pay for the phone, either by paying full price for the phone, or losing the discount.
Now if you are still on the old minute plans, then the subsidized upgrade is the way to go, but if you are one that keeps phones for a long time and don't upgrade every 2 years, it is costing you more money in the long run not changing to the Mobile Share Data Plan.