Chris Hill reflects on the longevity of David Letterman\u2019s career, as well as his role in changing the landscape of late-night TV forever.\xa0 Plus, in the wake of Orson Welles\u2019 100th\xa0birthday, Chris draws a parallel between Welles\u2019 struggle to make \u201cCitizen Kane\u201d and the growing battle between traditional broadcasters and live-streaming video apps like Periscope.