Okay, I've committed to SVN the following new Display2D methods which set and get the scroll position. The scroll position is defined as the x and y values *proportional* values between 0.0 (fully minimum position) and 1.0 (fully maximum position). Not tested well yet but it seems to work right.
public Double2D getScrollPosition();
public void setScrollPosition(Double2D val);
public void setScrollPosition(double x, double y);