One of the things we learned coming out of Comic-Con is that Adrian Pasdar will be joining Supergirl as Morgan Edge. Pasdar has a long history in the genre from playing Nathan Petrelli on Heroes, General Glenn Talbot on Marvel's Agents of SHIELD, voicing Tony Stark / Iron Man in multiple Marvel animated series, and the voice of Hugo Strange on Young Justice. In other words, fans know who he is. But who he's playing may be less well know.
From the trailer we see the Morgan Edge is bring brought in for someone to go up against Lena Luthor (Katie McGrath). Since McGrath has just been promoted to series regular, it makes sense for her to have her own subplots. But Edge has a place in the DCU and the Superman stories more specifically.
In the pre-crisis day, Edge was one of the wealthiest men in Metropolis and owner of the Galaxy Broadcasting System (WGBS) that eventually bought the Daily Planet. He would but heads with Perry White and moved Clark Kent to the television side having him as a traveling reporter and then eventually a news anchor. There was a storyline that had him tied to Intergang, the ciminal organization backed by Apokolips. But that turned out to be a clone created by a genetic lab called the Evil Factory. (You have to love the comics of the '70s.)
After the Crisis reboot, Edge was still the president of WGBS, but he had no ties to the Daily Planet or Superman. But he was connected to Intergang. He was exposed by Clark Kent and Cat Grant. Grant had been working undercover at WGBS. Edge went to jail where he penned an autobiography, On The Edge, which accused Grant of sleeping her way to the story on him. Upon his release, he funded a Superman Revenge Squad and became an anti-Superman / anti-Kryptonian pundit on a show called Edge of Reason.
The character of Morgan Edge was depicted at one point purposely driving over a raccoon. This stirred a huge fan response calling Edge worse than Lex Luthor, who treats humans like animals but would still not go out of his way to kill a raccoon.
Edge was once again revamped with the new 52 as the head of the Daily Planet and now African-American. He's a powerful and self-centered media mogul that sponsors the Challengers of the Unknown until they all quit because of Edge's business practices.
Edge was a villain in the Smallville television series originally played by Rutger Hauer then by Patrick Bergin. A variation on Edge appeared on Lois & Clark: The New Adventures of Superman, named Billy Church Jr. played by Bruce Campbell. Another variation was the David Warfield character played by Sam Wanamaker in Superman IV: The Quest for Peace. Edge appeared in Justice League episode Secret Society Pt1 voiced by Brian George. The WGBS network or Galaxy Broadcasting Company has been seen on the Super Friends animated series and in the Man of Steel.