The first was revealed in this months Doctor Who Magazine as Albert Welling, who has been cast in the role of Hitler for the story. Welling has had supporting roles in shows such as Cemetry Juntion, Heartbeat and Holby City.
The second casting comes in the form of Ella Kenion who according to our member Saber, has been cast in the possibly dual role of Margeret/Harriet. Kenion is probably most widely known for her various roles in a 3 series stint in The Catherine Tate Show as well as four series of The Green Green Grass.
For more on whats to come from the remainder of series 6, visit The Doctor In The TARDIS Forum