Kelly Linden provided some information on the Linden Scripting Language (LSL) function llGetAgentList(). The server maintenance package with this new function rolled to the main grid Tuesday. It rolled in spite of a problem. See JIRA item:
SCR-311 – llGetAgentList() with scope AGENT_LIST_PARCEL or AGENT_LIST_PARCEL_OWNER returns empty list when attached to avatar.
Server Scripting User Group
Of course those most interested in getting this feature intended to use it in avatar attachments. Frustrating. Kelly believes they can fix the problem and we’ll either see the fix pushed to the main grid or pop up in a release channel, depending on how well the fix goes.