SFX magazine has confirmed that Being Human star, Sinead Keenan, is set to be in David Tennant's two-part finale. Russell T Davies is apparently a fan of her, because after each episode of the BBC Three Sci-fi show he sent her an email saying "I’m loving it!" Toby Whithouse, creator of Being Human, also said, "He absolutely fell in love with Sinead who plays Nina. So he’s given her a part in David Tennant’s last two parter."
It's going to be good!