When I look at an open resource, the first thing I ask myself is "what
can I do with this, and what would I need to take into account to do
these things" Through that, I get a sense of whether this resource (whatever it is) could be used as a foundation or extension to some effort or idea that might come along. What I haven't been able to do, is to fit the OpenLearn termination clause into my understanding of the creative commons license. Looking at the first two reasons provided - financial sustainability and whether the materials must be withdrawn in the case that the project is not viable, and in the case that inappropriate materials are submitted - the proper course would be to cease the distribution of the materials. Beyond that, expressing the termination of any rights would be in conflict with the CC license.
(Though, IANAL!! :-)
The third reason is a little bit more interesting, in that it's looking at the implications of third party content. From what I could see on the website, many steps are taken to ensure that third party content is appropriately submitted in accordance with the CC license (which would mean the above applies,) if there are materials included in resources that do not fall under the CC license/have special terms - it's more logistical, which OpenLearn addresses by having an area for special restrictions to be noted. Though, if the special restrictions prevented an entity from duplicating or reusing that specific material, there wouldn't have been any rights granted that would now be eligible for termination.
OpenLearn mentioned that this is unfamiliar territory, and that is supported by even the most definitive and exhaustive analysis of OER's that is ongoing through the OECD's research with UNESCO / IIEP. These discussions have been great to read - and it's impressive that they are able to summarize it in these reports. Just reading the discussions, one post here or there could lead to one of those hours long sessions of playing follow the linker.
A couple good links on this:
http://www.schoolforge.net/IIEP_OECD_OER_forum_report.pdf (This document will soon be available on the IIEP wiki site, but I couldn't find it there yet - but wanted to share this because it points to a lot of important topics) It was also announced that the OECD/UNESCO/IIEP discussion will soon be focusing on Intellectual Property Rights - which should be a very interesting discussion that raises many new questions and provides some great insights.
Another link, that points to a couple documents (again from OECD) is here
http://www.oecd.org/document/3/0,2340,en_2649_33723_37815811_1_1_1_1,00.html