Though MF has indeed introduced " 'Maintain by Medifast' (a science-based diabetic program of low glycemic shakes, bars and soups targeted towards consumers with Type II diabetes and those who need to lose weight)" on the HSN - off their press release - the 6 regular MF "meals" don't add up to over 1,000 calories for sure.
I agree with you, MrsJim, it would indeed be cool to see MF reviewed in a more official manner than having brief on-the-surface studies done by JHU...
After doing a lot more casual reading last night on the web, it does look like, yep, the success rate for MF/other liquid-based diets is 5-10%. Yes, it works faster than traditional plans, but it does not change most dieters for the long haul.
I would not say Medifast is a gimmick though. I definitely believe in its quick weight-loss effect and the safety of it. Personally speaking, I felt great on it... and lost weight faster than ANY other program I've ever been on. I admit boredom was a factor, due to food variety restriction... but I think if a person is willing to tough it out, and get medical and moral support along the way as needed, it can work a lot of good.
I would say that MF is a step above Jenny Craig or NutriSystem if only for the quality soy protein base they use, which helps drop cholesterol, and the higher amount of protein which helps to preserve muscle as fat is lost. I know for myself that at the same weight of 191/192, on WW and MF, my waist and hips were each 2" smaller on MF. I'm going to go with the theory that these being my chubbiest places, the fat was burning off better with MF.
As I am now gearing up to go on MF again in a couple weeks, I now have a Tanita body-fat/muscle analysis scale, and I am keen to see just what happens to my "numbers" as I continue on the MF. (Unfortunately I do not have the same data for my WW years, but I am definitely going to be keeping an eye out for losing muscle! I expect to lose a small amount since that is the way of the dieting beast, I fear, but not any more than I have to!)
From my reading, it looks like under 800 calories really DOES REQUIRE one to get medical supervision on dieting. Over 800, well, not a bad idea by any means, but I'm not (only my opinion!) positive this is a necessity for those who otherwise have no medical issues, like diabetes, high blood pressure, heart irregularities, stuff like that. I'm sure an intro talk and lookover by a doc would be a good thing before embarking, regardless.
I realize MF is not a "normal" everyday way to lose weight. It can be too much money for some too. It's not a huge menu to choose from
It teaches regular small meals, but not of the create-your-own menu variety, which can create a crash-and-burn at the end for some as they come off it... but I do firmly believe it works well and safely if followed by the book. It's up to the user in the end to stay the course and really educate themselves along the way, so they can be one of those elusive 5-10% that STAY THIN. 

the SOLE issue I have with the Medifast marketing of the OTC is that it is NOT THE SAME as the medically monitored program and should not be considered as such. I did not see this noted on their website which is why I think it's IMPORTANT to stress here. From my own personal experience it's not the products as much as the professional, medical SUPPORT and basically 'retraining' the patient for the REAL challenge of weight loss - keeping it off -aka- MAINTENANCE - is absolutely essential for success (it goes without saying, perhaps, that my personal definition of success includes keeping the weight off!).