UPDATE: Sam Claflin ("Snow White and the Huntsman"), Eddie Redmayne ("Les Miserables"), Douglas Booth ("Noah") and Boyd Holbrook ("Hatfields & McCoys") are actually the ones screentesting for the role of Harry Osborn in "The Amazing Spider-Man 2," according to Heat Vision.
So where all that talk of Dane DeHaan, Brady Corbet and Alden Ehrenreich came from is anyone's guess. Or maybe they tested first and they've all since been dropped from the running. We may never know.
Anyway, we just hope that J. Jonah Jameson's in this one.