I think the closest to a developer list is at the AtariForge project pagehttp://atariforge.org/gf/project/firebee/
The developers are listed on the right sidebar.
It would be nice to have sharply focused goals with the people assigned to them clearly laid out for the public to see. It would focus the efforts and allow clearer communication.
But then again, maybe everything is lying dormant. It's hard to tell from the outside. I mean look at this page: http://atariforge.org/gf/project/firebee/tracker/
To-Do lists, Bugs, Support, Patches and Feature Requests...all empty, 0 posts.
P.S. If there are already such project plans and goal roadmaps, then I apologize. I couldn't find them online...I am not trying to criticize either, just trying to answer the OPs question. I love the firebee project