Michelle Ryan for companion?

[Abbie]

Could be a trial run? Like runaway bride?

Thats what I thought, or maybe she becomes a companion and is through the other specials as well?

[Layne]

From David-tennant (.com)
He will be joined by actress Michelle Ryan, who can be seen with him in the photos above filming on a double decker bus in Cardiff, and actor and comedian Lee Evans.
Michelle will play the mysterious Lady Christina de Souza. She said "I'm a huge fan of Doctor Who and very excited to be joining David Tennant and the Doctor Who team."
Executive producer and writer Russell T Davies said: "Michelle is one of the most sought-after young actors in the country and we are delighted to announce that she will be joining the team.
As always the script is being kept strictly under wraps. However, we can reveal that Lady Christina is a woman with a mysterious past who's going to have a huge impact on the Doctor."
Lee will play a character called Malcolm, whose life becomes connected to the Doctor's in unusual circumstances.
Doctor Who: Planet Of The Dead will air on BBC One at Easter.

Im looking forward to it I think Michelle can be good.