Seems it is still undetermined which nest they will use. I'm guessing the new one. I've yet to catch sight of a bird in the old nest, and they should have put soft nesting material in it by now. Comparing the old Decorah nest to the Davenport/Alcoa nest (link above), the old nest looks abandoned.

Maybe next year! Until then the Davenport cam is good to watch. There's a tiny square button below the screen that makes the view full screen.