During his nightly Countdown, MSNBC's Keith Olbermann yesterday had as his chart-topper Dallas County District Attorney Craig Watkins' "discovery" of docs and doodads related to the assassination of John Kennedy. Said the sports anchor-turned-Mini-Murrow, Watkins presented the materials yesterday "with a dose of provocation, whether intentional or not," then brought on as his special guest Gary Mack, curator of the Sixth Floor Museum at Dealey Plaza, who eagerly explained away that Oswald-Ruby transcript with which some folks are a little too fascinated, right at the arm. --Robert Wilonsky