Edit: It was later confirmed on Twitter by BBC reporter, Lizo Mzimba that they would both return.
The BBC officially confirms the return of David Tennant and Billie Piper for the 50th anniversary @bbcdoctorwho special.
— lizo mzimba (@lizo_mzimba) March 30, 2013
It was heavily rumoured earlier this morning before Lizo's tweet, but after an early distribution of the latest issue of Doctor Who Magazine, it is confirmed within an article that they are both set to appear, confirming those rumours, a low-resolution image is shown below.
|With thanks to John Bond for the picture!|