One terrabit per square inch for a billion years

How's this for interesting?

Scientists at Berkeley Lab have created a nanomechanical memory system capable of scaling, in theory to 1tb/square inch, and which will remain stable for a billion years. As I understand it, it consists of an iron particle inside a nanotube, and when you apply a voltage to it, it moves to the other end of the tube. You can probe the state of the particle without disturbing it.

This seems like a great thing, except that I have to wonder if you couldn't erase the data by shaking it, like an etch-a-sketch. Physical stability of the thing wasn't discussed. I'd also be concerned about the level of heat this will produce, especially in high densities. I suppose it wouldn't be any worse than transistors in the same space.

If these things work, scale, aren't as sensitive to motion as it seems like they should be, and are at least competitive on a cost-per-bit basis, (very very big IFs) it seems to me we might finally be looking at the technology that replaces that most ancient of data storage systems, the rotating magnetic media.

-JRS

P.S. How old is magnetic digital data storage as a technology? According to the wikipedia article, drum memory, precursor to the hard disk we know and love, was invented in 1932. Computers in the 1950s and 1960s used it as RAM. Therein lies a tale.