I know why they cut the "politically sensitive" scenes involving Harry and the new Minister and I can understand it.. but the fight scene at The Burrow, which replaces the scene in the book where he & Percy visit, is pointless and really horribly done. They could have easily left out this whole scene in order to fit the actual fight to the astronomy tower, or to include scenes involving Dobby & Kreacher.
They also do nothing at all to show Riddle working at Borgin & Burkes or discovering the teacup. Sure Harry knows about the Horcuxes and how many there are supposed to be, but how would he ever find out about this one otherwise? I have a feeling there's going to be some added clues along the way in DH, probably worked into the items willed to the trio.