Yes, the last option does give a lot of flexibility, and can be got going immediately with little effort at all. It could serve as a starting point to have a snapshot of what is currently published out there.
It will also be a useful starting page for others to take stock of, and may be able to get some media attention.
It also won’t require anyone with existing projects (those that already took initiative) to uproot themselves and move to another project, and does allow them to retain full management over their projects.
Yes certainly all the other forms of contribution are just as valuable to projects, but it may be difficult to see where say one of our local departments or citizens is say contributing to someone else’s project? If there is some way, we can certainly link to that contribution too eg. SA departments using, say Alfresco ECM, may contribute a patch that allows for SA localisation, or they may make a substantial contribution to updating documentation on that project, even though it is not one of our local projects.