Interesting feedback, considering I''ve been wanting to rip the current document collaborator stuff out in favor of something simpler. Based on my quick scan of that link it seems like the best mapping of those roles to document collaborator types in the current system would be:
Responsible - Document creator and co-authors
Accountable - Approvers
Consulted - Reviewers (who can view the document in any state and post comments in the author discussion comment thread)
Informed - Watches.
In general, we plan to keep the app agnostic as far as any particular methodology such as this, but it is a goal to provide a much greater degree of pluggability around document workflow, types, and versioning, so that direct support for something like RACI could be added via a plugin.
Excellent - good answer. Opening this up is the smart way to go, such processes vary, change, and evolve.