I'm looking for a service that would take an existing RSS feed and allow me to republish the items in it with a different schedule. Take for an example a weekly educational podcast that was done for a school year. I would like to publish those items again so that this year's students can subscribe to a feed that will give them one episode a week.
Take a look at Podiobooks. I know the founder and he has said in the past that they would be willing to publish other "ever green" content as well. The students would then just create an account and they get a personal RSS feed that can download the class each week.
Just a thought I have.