Sometimes, it helps to look at new technologies that will be adopted far in the future and ponder what the higher level implications are. NVM (non-volatile memory) is one of them, discussed at the SNIA NVM Summit in San Jose, California. Before you zone out, though, note that if this technology gets widely adopted, it will be as disruptive as SSD is for storage, and may change data centers in ways that server consolidation (enabled by virtualization) did in the last decade.
The NVM systems are still at demo or early stages, as shown in the photo to the right of an AgigA demo station, but there's a tremendous amount of investment and interest. NVM stands for non-volatile memory, but you can think of it as memory (fast, like RAM) that can replace storage (big, like hard disks). So some people refer to one use-case of NVM as storage class memory.