Brent Simmons:

"In NetNewsWire 1.0.3, we added an updated items feature. The idea is that NetNewsWire can often tell if an item is updated (edited) rather than new.

Updated items do not get marked as unread. There’s a reason for this: the majority of updates are inconsequential and you don’t want to be annoyed by them. They’re typo fixes, slight re-wordings, that kind of thing."

We often update our RSS summaries after first publication, and it would be interesting if more aggregators (I use Newsgator) would do this.