A Github approach might be more fitting for user created courseware. I am not hands on with Git, but it's clearly the way most collaborative, version controlled development is going. Well written, bug-free proposals could qualify for elevation to a CC github fork or some form of link in the community, and be elevated to a candidate level.. Success at that level would then earn it a place in the non-track curriculum.
The larger issue as I see it is scaling. Within a matter of weeks this community burgeoned to over 100k members, a large majority (I suspect) just getting started on CC. How many of these would be eager to create their own course? We already know from experience it would be about 1 per-cent, but that's still a thousand. CC is not equipped for that kind of load, as I see it, and is probably already straining under the cost of the earlier iterations of the courseware and site in general.
My two cents...