It looks to me like EPrints “Shelves” (http://bazaar.eprints.org/258/  - although the EPrints Bazaar looks to be not responding right now)  

are the closest in terms of functionality to allowing for sorted RSS export of search results from EPrints.

I have a question and a suggestion about it.

The question is: I would like to roll this out to admins and editors first, is there a way to turn off the shelves functionality for non-administrators and non-editors?

The suggestion: Rather than adding items individually one-by-one to a shelf, it would be useful if it was possible to assign a shelf to a Search URL/parameters directly, and have EPrints regenerate the shelf export nightly based on the search.

This would make the shelves dynamic, once they are set, they would update automatically as more content is added to the repository.

Tomasz