The end is in sight for spinning rust....
While flash based memory is nibbling at the edges of the disk industry, some new techniques are opening up prospects of even greater capacity and speeds in the next few years.
PMC stands for Programmable Metallization Cell, see this MIT review article.
PRAM stands for Phase-change Random Access Memory, some recent news seems to indicate that good progress is being made on PRAM as well as larger and faster Flash memory.
This SC07 article from The Register states that NRAM stands for Nanotube RAM, the makers claim that they will beat Flash on every metric in a few years time, and several of the big semiconductor companies are looking into the technology.