I am not sure if it's a trigger point or adhesions. In any case, if you draw a line down the delt right down the middle, the painful stuff starts at the top, slightly off the line, and then radiates forward slightly. It's terminus is about 2" down and 1" forward of the midline.
It doesn't seem to change locations or refer to another spot, but after about a week and a half of daily massage it's much less tender to palpation. The first few days it was more tender.
On a second look at some of the referral charts I have, it could be that it's referred from trigger points in my trapezius, as I have been working these as well.
I think foam rolling is a great tool. They speak quite a bit about this over a MichaelBoyle.biz.
It's all that damned rugby, I tell ya. Not that I regret playing or anything, though.