I wasn't sure at first if they were setting the data by doping the material, but on closer reading
"The engineers manipulated the nanomaterial so the electrons' spin within the material could be controlled,
makes it sound electrically re-writeable. Which is probably the only thing anyone's really interested in,
unless it was super-cheap. (i.e. cheap enough to replace pressed optical discs with ROM USB-storage.)
As bobjr94 hopes, it would be nice if it is that cheap, though, and optical discs are replaced by a standard flash storage standard.