It might be a good idea for Keith Olbermann and Rick Kaplan to give each other a wide berth until things cool down. I hear that MSNBC staffers in the Secaucus newsroom-studio watched in horror Monday night as the volatile Kaplan, the president of the cable outlet, publicly laced into the eccentric Olbermann, anchor of the 8 p.m. show "Countdown," after the latter eulogized lung-cancer victim Peter Jennings with a graphic rant about his own cancer scare. Olbermann - a former pipe and cigar smoker - is said to have looked stunned as Kaplan raced onto the set and shouted...