According to the Mirror article, there will be a new companion in the TARDIS from next year: "A show insider reveals: 'Martha will still be in Doctor Who, but her relationship with the doctor will have changed. The truth is that she loves him but he doesn't feel the same way. She is going to have to share him because he'll be getting a different sidekick. And this is a major addition to the cast.'"The article goes on to mention that Martha won't be in every episode next year, but will appear in the occasional episode for both Doctor Who and Torchwood. The item also repeats previous reports that singer Kylie Minogue will be the (only) companion in this year's Christmas Special.
Also dont forget that today at 10.30am on BBC 2 you can see the entire of the Doctor Who Animation including the unseen final part. Tonight at 7.05pm on BBC 1 the final episode of series 3 airs and it is entitled Last Of The Timelords with the Confidential of that episode being shown at 7.55pm on BBC 3.