Well we are halfway through 2012 and we still dont have on-die SSD controllers and SSD DIMMs. So even if we were to get Memristor based DRAM in DIMM form in two years, we have no easy way to scale up the memory support. That would set us back a couple years. And windows has no native support for installing and running from nonvolatile RAM.
I am assuming that memristors will replace DRAM and our OS will simply be installed onto this RAM. Right now windows would just stupidly handle this form of memory, it has not even begun to be optimized for non-volatile memory. Which means it will be wasting huge amounts of memory for basically no reason. Remember, there is no reason to load a program or its libraries into RAM if this RAM is the same RAM the programs are already stored on. Everything would essentially be already preloaded on bootup. It will takes years for a company like microsuck to adjust to this new paradigm, and they havent even begun. Nor have intel/amd, since they have no on-die high bandwidth nonvolatile memory controller.