Twins Castor and Pollux, who work with Cressida and the others in Mockingjay, have been cast! Curiously, the actors are not related themselves. ;)
Wes Chatham has been cast as Castor, while Pollux is being played by Elden Henson!
Wes Chatham has been in movies such as "The Help," and several TV series. Elden Henson was most recently seen in "Jobs" - and was one of the original Mighty Ducks!