Stephen Downes' OLDaily pointed to a Plugfest 9 presentation by David Wiley in the powerpoint format. However, if you watch the presentation itself (via the video link), you may pick up the clue from David that the days of teachers as a profession is doomed.
Wiley sets up a nice distinction between the "Centralized / Top-down Camp" (which favours intelligent tutoring systems, automated LO assembly systems, advanced visualization techniques and the like) and the "Decentralized / Bottom-up Camp" (which favours large scale self-organizing social systems, content creation, and more).
In the first camp, teachers are deliberately engineered out of the equation because if the design requires a teacher to students ratio, then the solution will not scale.
In the second camp, as David put it, the indigenous solutions in the online worlds do not have "teachers" as a profession.
If these two camps are the two ends of the scale, where are the teachers?
BTW, the summary provided by Stephen is the more accurate overview of David's presentation than mine here. I just point out one point here.