If you don't mind leasing the slider, you can turn to T-Mobile's JUMP! On Demand. With that program, you can pay $0 down (which is always the best part), and pay $34 for 18 months ($612). With this plan, you are entitled to trade-in your phone and exchange it for a hot new model up to three times a year. At anytime, you can purchase the device by paying off the remaining installment balance and "residual purchase amount."
If you are thinking about biting the bullet and paying the full retail price, you can actually save $20 by buying the unlocked version directly from BlackBerry. This model does support the T-Mobile pipeline. If you are interested in purchasing or leasing the device, click on the appropriate sourcelink. The BlackBerry Priv is available in your favorite color, assuming that your favorite color is black.
AT&T had an exclusive on the carrier-branded version of the phone in the U.S., which expired on January 20th. Both Verizon and Sprint will also be adding the slider to their equipment lineup in the not too distant future.
source: T-Mobile, BlackBerry via Crackberry