Just wondering if iScreensaver 4 allows for the Ken Burns effect or similar, now that OS9 has been laid to rest?
iScreensaver 4 has customizable fast OpenGL 3D motion effects for the Image layer.
Read more about it here:
http://iscreensaver.com/help/help07.shtml#effectTransition
And feel free to test for yourself, the trial download is free:
http://iscreensaver.com/download