Although cloud computing gets much of the spotlight, in-memory database management systems are the tipping point that will benefit the enterprise greatly once the technology matures.
The issue here, of course, is one of cost, with flash being significantly more expensive than disk and, in the case of in-memory database use, being accessed very infrequently.
Even for in-memory databases clustering provides performance advantage due to common utilization of large caches for input-output operations in memory, with similar resulting behavior.
In-memory database management systems will remove this need by making database access into something that occurs in memory chips -- which are much faster than disks.