In another act of competence it looks like DC Comics co-publisher Dan Didio left his office door open leading to the inevitable leak of the official DC character timeline. It breaks up the universe into different eras and gives firm dates to events.
While not much information can be gleamed from this snippet, it does show that Superman is 6 years older than Batman.
Is there a new crisis happening so DC can get its ducks in a row? Only time(line) will tell.