I would certainly be interested! As you have quite correctly pointed out, organisations like BALPA (British Airways Pilots Association!) are completely uninterested in Instructors (other than for membership fees!) I personnally contacted them to ask for advice on no fewer than 3 occassions, for info regarding unfair treatment at work, non-payment of minimum wage etc. They were quite happy to take my details, but they were never followed up, nor was I ever contacted despite my persistance! From my experience, organisations like BALPA are only interested in Airline Pilots. BALPA are however useful for loss of licence/medical insurance etc.
I believe that Union representation for Instructors has to be a good thing in terms of negotiating pay and conditions, and also improving safety. Incidentally, how many of you instructors (non career) actually have a contract? I have never had one until I recently accepted a post with a large proffessional training organisation.
Perhaps you should contact WWW, I believe he is very keen to offer advice as regards flying Instructor Unions. I`ll certainly become a member if it happens!!!