I knew you would be all over this, as am I... Time for more Google. Damn Dec, mine has been since around April also. I think after the 1st of the year I am going to tell the doc to do some cutting.
Ive been fighting it with PT, ART, meds, rest, typical rotator cuff exercises and nothing is really working. It starts to get better then any little work and it's bad again. I'm sure mine is 99% tendon related now, it's pretty isolated to reaching motion and the tendon the connects to the top of the shoulder but the MRI did show definite minor tears and a lot of arthritis.