Quote from: "Uncle Umpty"Tennent is suggesting the maybe Billy Piper could take over as Who and has also hinted that he could return at a later date.
I just saw that story on MSN, but he suggested no such thing. Some reporter asked if Piper would make a good Doctor Who and he replied "Why not?".
I would imagine that if he did reappear it would be as that human-beingified Doctor that's currently shacked up with Billie Piper in the parallel universe place.