The IncReASe (Increasing Repository Content through Automation and Services) project has released four plugins to facilitate importing e-print metadata from arXiv into an EPrints repository.
Here's an excerpt from the plugins' Web page:
Potentially, content in arXiv could provide a "quick win" for repository population. No arXiv depositor we have talked to date has objected to our importing their work into WRRO [White Rose Research Online]. From discussions with arXiv users, we are assuming that local deposit in WRRO with a "push" of data to arXiv may be difficult to achieve—we'd need to demonstrate some clear benefit to the depositor. arXiv serves its community well. A more likely model may be that arXiv users continue to deposit as now but IRs "harvest" data from arXiv (or perhaps arXiv will develop a facility to push material into local IRs).