This is it.
Who2’s first blog post, on 18 September 2005, covered the last words of Pope John Paul II. (“Let me go to the house of the Father,” they were reported to be.)
Post #100, from 6 September 2007, was “Still No Word on Steve Fossett.”
#500 was a personal favorite, on the amazing Star Trek bit part of King Abdullah II of Jordan.
That post was on 24 August 2008 — meaning we’ve averaged just about two per day since then. We’re speeding up.