I've been thinking of this since DC first announced the event...just what's going to happen afterwards?
Will everyone die from the other timelines? Will some flee to the new 52? Or will some timelines merge? I'd wager a little from all three. Maybe the two parter minis focusing these characters will affect storylines to come once the event is over? Maybe not but I'd be interesting to see how.
Oracle: Apparently a heavy focus on her relationship with Dick Grayson and Barbara's role as Oracle. Both are pretty much nonexistant the the relaunched universe. Plus the Worlds End series focuses on a version of the couple and their son Johnny.
Booster Gold: Obviously this one will connect to the overall story the most. It may set the new status quo of soft reboot after the event but also what's to come for Booster and Rip.
Batgirl: Hard to say as Stephanie was recently set up as Spoiler although her Batgirl ties were toyed with by Gail Simone. The only thing that I can guess at coming from this is the introduction of Cassandra Cain.
Blue Beetle: Ted Kord has been introduced in new 52, he's just a normal guy at the moment. The Ted that shows up here did make a comment wondering who Booster was in his one shot. A Easter Egg for the fans or something more?
Titans/Flash: Both of these titles focus on the children of former kid sidekicks. Having these children crossover would help legacies while keeping the heroes young.