What other options do they have?!?

Potter Stars Staying On for Fourth Movie
Emma Watson has announced that she and fellow HARRY POTTER film stars Daniel Radcliffe and Rupert Grint have decided to stay on and star in the fourth movie, HARRY POTTER AND THE GOBLET OF FIRE. The third film is currently in production and shortly after it is done, the fourth will begin. After being asked if they’ll stay on through all seven, Watson said, “WeĆ­re not up to speculate on that. One movie at a time.”