If motherboard standoffs were longer, the entire underside of ATX motherboards could be populated with Nand Flash chips + matching sockets: the chips could be sold as options, allowing the user to decide how many to purchase and install, or the chips could be pre-soldered.
A similar approach could offer standard laptop SO-DIMM sockets on the underside of motherboards (with longer standoffs to make room), as a way of supporting much larger RAM subsystems e.g. for loading an OS directly into a ramdisk pre-formatted with a specialized BIOS option.
With RAM sockets on the underside, that will free up more "real estate" on the motherboard's topside.
The future will definitely see more miniaturizing and much higher densities e.g. SO-DIMMS @ 8GB, 16GB and 32GB are now foreseeable.
And, "large" does not need to imply "super fast" because a ramdisk running on DDR3-800 RAM is plenty fast for high-speed storage hosting NTFS partition(s):
http://www.supremelaw.org/systems/superspeed/RamDiskPlus.Review.htm
Thus, with 128-256 GB desktop RAM subsystems, it would be easy to carve out 20-30GB for a ramdisk dedicated to the OS, with a slick backup system that re-loads an OS drive image e.g. from SSDs, after a total system shutdown that turns OFF the RAM power supply e.g. for routine maintenance / upgrades / etc. Enthusiasts will have a field day with such tech (I predict!)
MRFS