Yes, per folder you can set it. I want it for ALL folders. I may be importing many feeds (over 200) and I will be using the "All Stories" feature to read through them; hopefully in the order they came in.
I would really like to be able to read old-to-new, but also see previously read stories. Would it be possible to set the feed to be ordered old-to-new but start the list position at the point of the oldest unread post, rather than the oldest post found?