I actually don't check this forum that often, except these days where I'm looking for a Thambar lens (once the cheapest Leica lens, now a collectors item).
The Extension Course starts off with the basics. For Leica users this is not big news as you as a Leica user usually only have the buttons and dials needed for controlling light. For a dSLR user this part is frustrating/life-changing in that the basic dials and buttons aren't available for control, but instead 80 other controls are.
In any case, I've found the basics of photography and how to control an image in terms of light has to be mandatory for the extension course (as well as my seminars and one-on-one training). If it's not covered, it's *always* going to cause problems later (you can't use a reflector properly if you don't know how to control the exposure 100%). I had one student who said he had learned things about cameras and photography he didn't know for 22 years taking photographs. So the basics are very important and are usually overlooked because they seem to fundamental. But try to explain white balance to somebody and you might find out that you actually don't know exactly what it is. But you can (and should), it's not a secret subject, just a confused one.
From there the extension course move into the things people usually want to know about, which is photographing people, street photography, composition, timing, white balance, message in photos, quality in photos, etc.
The extension course was originally (back in February 2010) made because I had people from the Philippines asking to come to the seminar in New York. I frankly felt that was too much trouble, why I made the extension course. It's less money and can be done on and off from home, in between work, marriage, child birth and all.
Essentially it's the same, except the extension course has more assignments and more theory (as there is no time limit as in a seminar), which compensate partly for not being in the same room.
There is feedback from me on assignments, as well as individual questions (everything from lens choices, upcoming stage photographing, wedding photography, etc is being asked and answered). In the beginning the extension course was meant to be in steps where you would send in the assignment/answers, and then I would answer and send the next step. This turned out to be hard to control as I could be away for days and unable to answer; which is why the student now gets the first 11 parts in the first go and can move on with or without my response. Though all get response to each step.
Just today I got a call from a person in Miami who hadn't gotten any response since his first homework two weeks ago, and I just found his and some others homework. So when I go to London in four hours, I know what to do the first day there.
In any case, the seminars (and extension course) perhaps originally was intended to raise each and every photographer to a very high level of photographic skill. In practical terms, this does not happen.
What does happen is that you will find students on many different levels, and the course will generally inspire people to do much more photography, become better from the level they were, and far more enthusiastic about photography - and certain in terms of what equipment to use (and what not to spend time and money on).
I have developed a new theory as we're discussing ways to teach new Leica owners (of M9, D-Lux, X1, etc) Leica photography from the very beginning. My theory - or perhaps observation - is that if people fall for the a sexy camera, but then fail in getting good images from it, they tend to stop photographing and become collectors instead. Nothing wrong in collecting and admiring cameras, but you bought them for an original reason, and that was the possibility to create art and communication with them. So I want to learn people how to do that and get them rolling on that part.
I feel I have many satisfied students (especially when they get to the composition and assignments part). If one feel it's the wrong course, they can ask for a refund and will get it. 3% have asked for that so far and gotten it. It's hard to tell how it feels doing the course. Some are really into it, spending many hours on assignments and testing stuff, and I hope nobody feel as I sometimes do when I look at video tutorials (which I seldom complete viewing). Photography should be an adventure and a fun journey, and it can be.
Hope this was of help.