Sorry for the delay in responding, but somehow your posting fell below the radar. In short: no, at the moment, we only provide simple Dublin Core (ie. DCMES 1.1) from OJS and the like as part of the OAI spec. However, if you need richer metadata, you might consider trying to harvest MARC21/MARCXML or RFC1807. We are currently working on an overhauled metadata framework which will make crosswalking to other formats (including DCTERMS / qualified Dublin Core) much easier. It should be available, along with some new metadata schemas for harvesting, later this year.
Hope this helps,