BBCAmericaShop lists a 'Merlin - The Complete Series' box without mentioning a release date, while
BBCCanadaShop lists the release date as after 22 July, 2014, and
TVShowsOnDVD mentions a release date November 12th, 2013.
AmazonCom lists the box as currently unavailable We don't know when or if this item will be back in stock. (you also can't pre-order the box, just add it to your wishlist). So all we know for now is that this box will be released eventually. Let's hope it'll be way sooner than after 22 July, 2014.
Special Features: Audio commentaries by cast and crew, The Making of Merlin, Video diaries, Photo galleries, Deleted scenes and outtakes, Wallpapers, Storyboards, Fan Photos, All new clip featuring the Merlin Cast at Comic-Con 2012 [the one Bradley didn't attend...], exclusive to the set!