We've got the answer for that one - now that the movie has come out. Harry and Hermione really do dance! It is a very cute scene which shows that there could have been something after all between harry and hermione. once Ron leaves them alone, Harry calls Hermione to dance so that he can cheer her up. This scene is criticized by many Harmony bashers but is adored and held as a proof for the harmony ship's existence by the harmonians.
Ask me what I think Anyone who is right in their brains cannot call Harmony delusional after watching this scene.