The default value is false.
The following image, from the "Page Control" demo in the "iOS Standard Controls" sample, shows the application in the middle of a swiping animation; portions of both the white and gray subviews are visible. If UIScrollView.PagingEnabled were left to the default false value, if the application user's finger was lifted at this point, the scrolling would stop with both views partially visible. If it were true, the closest view would "snap" into alignment (in this case, the white view).