Exploring OER repositories

I've been doing a very introductory exploration of what people are doing out there in terms of repository software/platforms for OER (Open Educational Resources). These are my preliminary notes-to-self, which I'm posting primarily in the hopes that someone more knowledgeable will come along and correct any fundamental misunderstandings / point me to useful resources.

So, after a very brief scan of a few sites, I get the impression that:

• Where the aim is to just put up course outlines, lecture slides, handouts, and the like - maybe the occasional multimedia file but no wholesale recordings of lectures etc - something like a prettified dSpace would be quite suitable. For example this is used by Jorum (a JISC-funded service).
• However another factor would be the intended audience for the resources. Jorum seems primarily aimed at educators sharing resources with each other. By contrast, sites aimed at prospective students tend to be more complex, often based on Drupal (an open-source content management system) eg Open University (Drupal/Moodle) or Michigan’s OERbit (open-source software based on Drupal). Of course these also tend to include a lot of multimedia content, especially lectures.
• A third option would be to put material directly into an existing repository - www.oercommons.org, lemill.net, www.curriki.org, cnx.org and many others curate OER. This gets the material out there without having to maintain a platform yourself. But a lot of educational material might make best sense in a national rather than international context (cf OERAfrica)

I came across mention of Equella; this is digital repository software designed such that "faculty and instructional designers can search and find the best learning content for the desired outcome or activity at hand, whether that content is OER, licensed (paid-for) content, or user-generated content". That is, it seems focused on internal users, not prospective students, and OER is only one part of the intended content, hence a prominent feature in the sites using it being that they require a login (or the workaround of "guest access"). From a glance over the highlighted example, I don't see its offerings as an outwards-focused repository for OER being substantially superior to (open source) dSpace's.

Really useful resources:

• Creative Commons wiki page on OER
• UNESCO's Guidelines for Open Educational Resources (OER) in Higher Education (pdf)

Getting further along, licensing and following standards that would allow harvesting are really important. But thinking for now just about platforms, what else should I be looking at and thinking about?