The Pyramid Picture
To illustrate the idea of how HA will grow over time, I've found this picture to be helpful. The idea is that as cost goes down volume goes up geometrically, not linearly.
And, in an OSS development project, developers go up with volume. Therefore, the net result of open source HA software coupled with low-cost commodity hardware is a huge increase in the number of users and applications of high-availability systems.
See Also
WhoWantsLowAvailabilitySystems[1]
References
| [1] | http://www.linux-ha.org/WhoWantsLowAvailabilitySystems |