James Hibberd over at EW once again has the scoop, revealing a series of character posters—focused, interestingly, on the Lannister bunch—done in striking black-and-white and featuring the ominous phrase, “Valar Morghulis”. Along with the posters is a very brief video, focused on Tyrion and giving a sense of the sort of predicament he will be finding himself in this season.
All in all, very much a mood piece, setting a tone for what season 4 is going to be bringing. Hibberd hints that more posters and videos shall be hitting the web soon enough, doubtless in a similar vein.