Let's say you got a shiny, new phone and contract for Christmas, or sometime before 1/10/14, by switching to framily, you're essentially knocking a full year off your contract. You're remaining contractual obligation to sprint becomes 12 months from framily activation. After the 12 months, you're contract free, and able to upgrade if you choose using their new "easy pay" plan.
No catch, once their "limited time" time frame is established, you'll avoid that fee.