Thanks to SnitchSeeker we can now reveal that Augusta Longbottom, Neville Longbottom’s grandmother, has been cast for Deathly Hallows! Ninette Finch has been chosen for the role and she had this to say:

Yes I am playing Augusta Longbottom although it is not a very big part… I have also played a couple of witches and was one of the people on the Millennium bridge when it was under attack.