Phase change memory goes nano

It seems that there have been some new developments in miniaturising phase change memory devices. This is a good step towards cheap, robust, mass-produced, non-volatile memory. I imagine that there are further optimisations that could be done in an end-user application of the technology. For example, at the moment they are producing the electric field for each individual bit when setting the material's state to crystalline. This could probably be parallelised by having an area of 256-bits heated to release the crystallised elements back to the amorphous state and then all the bits out of those 256 that need to be set to one would be heated while an overall electric field is applied. This way a whole chunk of bits could be programmed all in one go. Alternatively, the erase could be done as described and then with the electric field applied each of the bits could be programmed serially while the field is on using a 16 x 16 grid address, saving on the number of address lines that would have go through the device.