Earlier in an interview with David Heyman, director of HP films 5 & 6, he let slip that WB had added a scene into the film that was not previously there.
In a wedding scene in book seven of the Harry Potter series, filmakers have added a dance scene with Harry and Hermione not shown or mentioned in the books that filmakers think will "go with the overall plot of this film".
If this is indeed true or not, either way, fans will have to find out themselves when the film premires in November 2010.