From the wikipedia article on this class of memory (http://en.wikipedia.org/wiki/Phase-change_memory http://en.wikipedia.org/wiki/Phase-change_memory), it seems

From the wikipedia article on this class of memory (http://en.wikipedia.org/wiki/Phase-change_memory http://en.wikipedia.org/wiki/Phase-change_memory), it seems like this technology has been around since the 1950s-1960s. That's the perspective that you should view the IBM announcement though. It seems like the IBM technology might be the final step towards mass adoption.