According to Variety, Batman Arkham City's prequel is in production for the next generation of consoles and will likely bow in 2014 at its earliest.
The story will pick up before the happenings of Arkham Asylum and Arkham City where Batman meets Joker for the first time. It is also expected Batman will team up with other DC's justice league characters. For those familiar with the comics, this consists of Batman, Superman, Wonder Woman, Green Lantern and The Flash.
With this new installment Warner Bros is willing to give the Justice League characters more recognition before releasing a movie starring all the characters somewhere in 2015. It makes sense that they are eager to replicate the success of Marvel's and Disney's 'The Avengers' movie which revenued a 1.5 billion income this spring.
Is it a smart move to bring in other characters into the batman universe? Can this prequel still be called a Batman game? Only time will tell.