Sounds to me like it is how I though... Installment payment + $10/month + downpayment.
From http://www.zdnet.com/t-mobile-announces-new-jump-twice-yearly-upgrade-program-7000017906/:
"I used to changes my smartphone every couple of months, but over the past couple of years they have gotten better and better so I now can be seen with a phone for 6 to 10 months. I rarely use the phone subsidy on carriers though and typically pay full price for my gear.
The new JUMP! option for T-Mobile is a $10/month program (just a few dollars more than you pay for their current carrier handset protection) that lets you bring in your current phone and trade it in for a new one financed with their zero interest Equipment Installation Program (EIP). Any remaining EIP payments from your previous phone will be eliminated by the trade-in. You get to purchase the new phone for the same low upfront cost that new subscribers are offered, all still with no annual service contract.
I haven't ran all the numbers to see how the bottom line shakes out, but at first glance it seems like a good program to keep existing customers coming back to T-Mobile."
oh my god.....that's another way of saying "Renting" an iphone. who ever buys into this is an idiot when the program goes live.