I’ve been looking at this from the other end of the spectrum, the workplace. There is a demand for the equivalent of PLE in the workplace (I’m running courses at the U of T on the subject). One way of looking at this is as personal knowledge management (though I’m shifting that term to “network learning”). The concept of PLE is not unique to educators, as work and learning become integrated in a networked society.

My posts on PKM (network learning):

http://www.jarche.com/tag/PKM/

My personal learning journey:
http://www.jarche.com/2010/08/a-personal-learning-journey/

PKM also breaks down hierarchies, as the usefulness of centralized content repositories becomes rather questionable in a networked business.