Microsummaries in Firefox 2

Firefox 2 is introducing some interesting feature called microsummaries. Normally web pages have static titles, which appear in the title bar and are used when bookmarking a web page. Microsummaries allows those previously static bookmark names to be dynamic and change along time. I'm still puzzled about the practical usefulness of this feature, maybe I don't understand it well still, but perhaps its importance becomes clearer when it is combined with RSS/Atom feeds. Maybe that's why Firefox is introducing it, having been a leader in supporting feeds since earlier versions of Firefox.