James Gunn confirms this reboot will not cover the origin story:
Fan-freakin-tastic! The last thing we need is another origin story. The Batman worked and its a copycat world after all. Just don't copy the darkness part.
Besides, everyone knows Superman's origin story anyway. Year two (or thereabouts) is much more interesting.
“Look, you can’t put the Superman #77s with the #200s. They haven’t even discovered Red Kryptonite yet. And you can’t put the #98s with the #300s, Lori Lemaris hasn’t even been introduced.” — Sam
“Where the hell are you from? Krypton?” — Edgar Frog