If I had a pond on my property, I'd probably put them in it if there's not snapping turtles. I've heard some people introduce their ducks to ponds, and the ducks are afraid of it at first. They really don't care for new things!
I would love to put them in there, but the pond is not completely on our property (5 acres), and it is all the way at the edge. I can't be certain what all lurks in those water either. And Miss Lydia brought another point about diseases from other waterfowl - there are always wild geese at that pond. So as much as I would love to let them explore, it's probably not the best choice.