Auto-download only newly released podcasts from feed

I'd love to see an option to auto-download only the podcasts that are new to the feed - that is, those released after a certain date, such as the subscription date. The current auto-download feature assumes that "new" is anything on the feed list I haven't played, which is too indiscriminate. This would be great for podcasts where you want to hear everything current while retaining the ability to browse the back catalog and pick and choose what you want to manually download from it. As it stands you have to either auto-download everything displayed or put up with manually downloading the new items.

Thanks guys.