This month’s passing of TV pioneers Roone Arledge and Edgar J. Scherick, along with the death of Sylvester “Pat” Weaver earlier this year, leaves few living television pioneers.Arledge’s legacy spanned “Monday Night Football,” instant replay and personality-driven news shows like “20/20.” The Harvard-educated Scherick created ABC’s “Wide World of Sports,” whose camera and sound techniques revolutionized sports coverage. Weaver created shows like “Today” and “Tonight” for NBC. He also helped wean networks from sponsor-financed programming, ushering in the modern, ad-driven broadcast landscape. The void left by these legends prompts questions for those in the biz: Who are the innovators of today? And is there still an opportunity to innovate?