Suicide Squad, is all about the villains. We've seen big screen adaptation of anti-heroes, such as Marvel's The Punisher, but this is all about the bad guys. They're granted reprieve from incarceration in exchange for carrying out dangerous operations for the government.
The names of the actors hired for the roles are causing the biggest stir -- Tom Hardy as Rick Flagg, Margot Robbie as Harley Quinn, Will Smith as Deadshot, Cara Delevingne as Enchantress, Jai Courtney as Boomerang, and Jared Leto as the Joker. That's a decent lineup of talent.
Protagonists, the leading characters whose actions drive the story, don't necessarily have to be heroes, but they do need to resonate with the audience, and those villains listed above have been fan favorites for a long time. Harley Quinn has been beloved since her debut on Batman: The Animated Series, and the Joker has always stolen the show, whether voiced by Mark Hamill or played by Cesar Romero, Jack Nicholson, or the late Heath Ledger. Jared Leto will have some big shoes to fill.
In the comics, Rick Flagg isn't really a traditional villain, so I awesome this will be about his heroic journey, although I would have liked to have seen Tom Hardy take a stab at playing Bane again (a new version, since he was killed off in The Dark Knight Rises). Having Will Smith in the cast is interesting, since I can't picture the superstar playing second fiddle, but that might create the perfect dynamic as these loose cannons try to work together, each with his or her own agenda.
The movie is scheduled to be released in 2014, and don't be surprised if we see a familiar cameo or two.
Not to be outdone, Sony Pictures was also planning to have a Sinister Six movie, centering on a team-up of Spider-man villains, but it looks like Warner Bros. will be beating them to the punch.