I met one of the proprietors of Mountain Biking School at the Pinnacle this past weekend. He was there trying to raise some awareness and I believe giving out some vouchers to podium finishers. He seemed like a stand up guy trying to do something he was passionate about. Just to respond to some of the points made above:
I can't speak to the exact relationship between the School and NEMBA other than that they have been buying advertisements and I do know that their use of Russell Mill was vetted as mentioned already.
As to the cost, it may seem steep but compared to any other form of professional training or higher education (cost per credit hour) thats actually pretty standard.
As to liability and private companies using public land I don't think there is really any issue there. Guide services use public land all the time, most have some sort of agreement/permit (like this school has with Chelmsford) be it rafting on a river, hiring a climbing guide, etc. Its not uncommon. If I hired a guide to help me hike the AT through New England and fell and broke my leg would the AMC and USFS be liable? I'm no lawyer but it doesn't seem likely.
I suppose you could go back and forth forever on a value comparison of getting free advice from NEMBA members compared to paying for a structured MTB clinic. Probably good arguments in both directions almost all of which would probably be subjective to a certain extent.
I agree with Slappy. Strong feelings? Check out the free clinic and go from there.