Following on from my last post on this thread, I had another reply from NewsGator:
'FeedDemon v1.5 will continue work as always even once the new version is
released. It's a separate product and will remain that way. The
difference is that the new v1.6 is designed to integrate and sync with
NewsGator. You can still use 1.5 as long as you choose.'
I have played around today with a number of related products - Onfolio, Omea Reader, SharpReader, GreatNews, Folio First, and one or two others (I followed links from the Wikipedia entry on RSS) - and I don't think anything touches FeedDemon for its clarity and neatness. I just love the design and layout of this program!