I don't have a good answer for you, but you'll probably enjoy it :)
Ben (I think?) wrote a document describe the roles "the gatekeepers' play when I was traveling across Canada for 3 1/2 weeks. It would give you a little more information, at least.
Unfortunately I can't find it! It certainly needs to be linked to from an obvious place.
At least I think I saw such a document...since I can't find it I'm starting to question my own memory!
As far as the OpenACS 4.x project goes, the status report is the best place to find out who has stepped forward to take responsibility for various packages.
We do need something that fleshes out the informal structure of this (dare I call it) organization for folks. It would be good place, perhaps, to flesh out areas where we need folks to step forward and tackle stuff that's being left undone. Some of the things on Carl's list are, in a sense, metatasks (not attached to any particular project), while some are project-oriented (4.x toolkit documentation is part of the 4.x project, 4.x testing part of the 4.x project, etc).