very thoughtfull comments Oshyan,
in fact you have just about summed up better than i could have the conclusions i came to (except for the part that i preferred drupal much more than mambo/joomla).
as you said exactly, for the stated goal of collaborative writing, wiki is a much better match in terms of functionality.
and indeed if you look up at top of this page you will see a "wiki" button. i went back to wiki (mediawiki) instead of drupal, because it was just a better match for the task, despite my frustrations with permission management. i have come to appreciate wiki for the ease of collaborative editing, and the rich functionality in terms of loooking at history of changes and being able to easily roll back stuff that is not desired.
so i'm a reluctant wiki convert i guess

ps.
http://www.opensourcecms.com/ is a fantastic resource, i agree completely. anyone considering adding a content management system to their site should make that there first stop.