It would be great to see some of these pop up as integrated features on motherboards. Having something like that could make for some small designs, lower power requirements, and fewer components. Having a dedicated drive for the OS would also leave an extra drive (or array) open for performance. If an add-on drive is being used, the integrated could be used like the new non-volatile RAM, a type of cache, or just an extra drive.
All assuming it has reasonable costs < $1/GB.