I consider myself a jaded superhero/science fiction fan, but I'll admit the setup for next issue threw me for a loop. I was expecting Melodramatic Superhero Time Travel Plot Cliche #4, which gives the protagonist the exact opposite objective.
That is a way to make things interesting, though. Its highly unlikely DC will let them succeed, which means we'll get to see the good guys deal with failure and scramble to fix what they can. However, if they do succeed (and we get a sliver of a chance of this because DC has a big crossover coming up and we know they like to juggle shit around when they have crossovers planned) we get to watch several DC writers frantically try to adjust to the new timeline.
Granted, both options could result in the writers and editors falling flat on their faces, but success really wouldn't be the least bit impressive if there wasn't a decent chance of screwing things up very badly.