Some of the issues you mentioned have actually been fixed during the after conference sprint, but still resides in a branch:

• Select target workflow state for feed items.

• Links point to the Plone item instead of the original item on the Feed listing and a link to the source is added to the feed item view.

• Date format changed to Plone’s default way, that was a left over of the initial implementation for our customer.

RSS support should be easy. Feedparser (which does the heavy lifting) parses it alright, we just might need to grab a different fieldname or compensate for a missing ID or so.

There are one more issue: I’m a bit worried about large sets of items myself. Because of the extensibility we effectively need to wake up every object to see if it implements some interface. That needs a catalog field for it to scale. I know there’s some generic catalog solution being discussed.

But all in all, it seems to work real well. At least for our original client (which is the reason behind the strange date format, that should change).