Responding to a similar offer by rival T-Mobile, AT&T today said it would introduce a rollover data plan for some of its customers. The company has also started offering the BlackBerry Classic and BlackBerry Passport smartphones. From Jan. 25, 50 million AT&T subscribers under Mobile Share Value plan can move their unused data in a given month to the next one.

But unlike T-Mobile's plan, which allows users to keep rolling their data up to a year, any unused rollover data on AT&T's plan will not be transferable beyond one month.

AT&T also today announced the fruits of its partnership with BlackBerry. Mobile professionals will be able to get one of the BlackBerry Passport or Classic for as little as $49.99 on contract – or even less.

Coming with rounded edges and not the square design we have seen so far, the BlackBerry Passport for AT&T comes packed with a 2.2 GHz Quad-Core Qualcomm processor, a 13 Megapixel Camera with Optical Image Stabilization (OIS) and 32 GB of Storage (expandable by an additional 128 GB via a micro SD Card).

In addition to the standard core features of BlackBerry OS 10.3, it also gives users up to 30 hours of mixed use. Features like BlackBerry Assistant and Blend are also included.

The BlackBerry Passport will be available in the near future for $0 down on an AT&T Next plan at $21.67 per month with AT&T Next 24, $27.03 with AT&T Next 18 or $32.50 per month with AT&T Next 12. You can also get the smartphone for $199.99 with a two-year agreement or at no annual commitment for $649.99.

The newly-released BlackBerry Classic will join its larger sibling on the carrier. It includes BlackBerry’s iconic QWERTY keyboard, trackpad and navigation keys, making it easy to communicate quickly with one hand.

Although familiar in appearance, the Blackberry Classic upgrades the BlackBerry Bold 9900 experience with a three times faster browser, 60% larger touchscreen and comes with BlackBerry’s 10.3.1 operating system, offering users access to commanding features including BlackBerry Blend and BlackBerry Assistant. It is also equipped with a 2MP front- and 8MP rear-facing camera with enhanced optics and upgraded imaging sensors.

You can purchase the BlackBerry Classic for $0 down on an AT&T Next plan at $14.00 per month with AT&T Next 24, $17.50 per month with Next 18 or $21.00 per month with AT&T Next 12. You can also get the smartphone for $49.99 with a two-year agreement or at no annual commitment for $419.99.