Harry Potter the Quest released a new BTS feature on Harry and Dumbledore's relationship in the film series, focusing on Dan with Michael Gambon and Richard Harris, and featured new on-set scenes from King's Cross in DH2.
Harry Potter the Quest released a new BTS look at Ron and Hermione's relationship throughout the series, leading up to their kiss in DH2, and featuring the kiss itself and a bit of new on-set footage of it between Rupert and Emma.
Target released the first preview of Morgan Matthews' documentary on the making of the DH films, which will be part of the DH2 BD set this fall. That feature, with tons of new BTS clips from the final films, can be seen here.
A bunch of new on-set photos from DH2, including of Voldemort in the final battle, the trio in Gringotts, and more, were featured in the trailer for the upcoming Harry Potter Page to Screen book. That can be seen here.