But the prophecy was not an element introduced in the prequels... it dates back to the second draft of the original SW:
"…And in the time of greatest despair, there shall come a savior, and he shall be known as THE SON OF THE SUNS."
?Journal of the Whills, 3:127
Maybe this is not the actual text of the prophecy the prequels refers to (even if it has been retconned this way!!!) but the idea of a prophecy in the SW saga dates back to 1975! :)
...what now worry me: is Ady going to keep the references to the prophecy?