Cloud computing refers to the trend of utilizing the Internet to run software applications rather than being dependent on the operating sysem (i.e. XP or Vista) of a computer.  An obvious example of this would be Google Docs, but others like Adobe have been moving more towards creating software that works online through the browser like IE and Firefox (now Google's Chrome).

I am a junior high tech teacher and for the last three school days I have been off due to a serious maintenance problem in my school's building.  Of course I'm thinking that DE has a unique advantage here in that it is not dependent upon maintaining a building infrastructure to deliver courses.  But have we just shifted the dependence from buildings to servers?  Really, who has ever heard of a server going down?  Nah, never happen.