The biggest hits on prime time, network TV this season reflect America's ethnic diversity—on screen and behind the cameras. How to Get Away with Murder, Fresh off the Boat, Jane the Virgin and Empire don't just feature black, Hispanic and Asian actors in major roles. They're good shows — produced by ethnically diverse crews of producers and writers. With help from social media, they've drawn the live audiences dear to advertisers, and they've delivered high ratings across the board. But skeptics say this has happened before, and Hollywood's executive suites are still dominated by white men. How long will it last?