This April 3, 2013 publicity photo released by NBC shows host Jay Leno on the set of &quot;The Tonight Show with Jay Leno,&quot; Season 21, Episode 4437, in Burbank, Calif. The role of female talk-show hosts in late-night TV network history, all 50-plus years of it, can be summed up in two words: Joan Rivers. It takes just another two _ Arsenio Hall _ to do the same for minorities. There&#x27;s no indication that&#x27;s going to change in the latest round of musical chairs involving &quot;Tonight&quot; and &quot;Late Night.&quot; (AP Photo/NBC, Paul Drinkwater)