Looks like DC Comics is planning a line-wide crossover next year, as Dan DiDio, DC Comics Co-Publisher, recently hinted as much.
In an interview with ICv2, DiDio let it be known that readers will see better continuity through the books and mentions a crossover for next year.
I'd love to be able to celebrate the anniversary of "The New 52" with something that feels so special and something that unifies the line thematically (maybe not story-wise). We're leading to probably our first crossover event in the latter half of next year, but you're going to see a better continuity developing through the line.
Now this would be the first major crossover to grace the DC comics, but we have seen a Batman crossover, Swamp Thing/Animal Man and two more upcoming crossovers with Green Lantern "Rise of the Third Army," and the "Trinity War" Justice League story from FCBD.
No further information is known about the event.
Cosmic Book News will be sure to update.