So Um... Like I said above SPOILERS or at least potential Spoilers so if you want to you know stay unspoiled for episodes don't come in here.
I found it by reading some one's Lj and then looked it up on the main doctor Lj where it was posted too. I think it's from The Sun.
The link for one of the lj sites it is also on is here:
Link RUMORS
BILLIE Piper will return to Doctor Who with ALL the Time Lord’s former companions as part of David Tennant’s final episode.
Billie, 26, will again play Rose Tyler and teams up with other sidekicks Donna Noble (Catherine Tate) and Martha Jones (Freema Agyeman).
The trio will join forces to take on the Doctor’s revived arch-enemy The Master, played again by John Simm.
The episode sees the Timelord regenerate into the new Doctor (Matt Smith).
An insider said: “This will be the most exciting episode Doctor Who have ever done. We really wanted to get all the companions back on board as a fitting send-off to David.
“And of all the enemies for him to face in his final episode it makes sense for The Master to be the main one. Getting Billie to agree is a real coup, but she loved working on the show so much it didn’t take much convincing.”
REMEMBER FOR NOW THESE ARE JUST RUMORS
So I don't really know what to make of this. I'm a little worried and a lot confused. If she comes back (again, some more) what do you think your reaction will be?