Gwendoline Christie has been cast for the role of Brienne of Tarth.
The other girl isn't short, Gwendoline is 6'3". (Fourth pic down, in the blue dress) For comparison the fellow playing Jaime is 6'2" so she will actually look down on him, just like the book.
Hope she hits the weights, she's got the height and probably can be made
Hollywood Homely by just leaving any makeup off and messing up the hair a bit.
Now we need to know who's going to play Stannis, Davos and Melisandre...
(hope I don't get in trouble for hotlinking...)