It was rumored for PSN as well as Live back a little while ago, so it'll probably end up on PSN, hopefully, with PS2 games as well. Gameshare prices for DC and PS2 games is awesome.
Since it was leaked for live, maybe psn will come out from hiding and confirm it's for both soon. Unless, of course, they decide to deny it up until E3, because it's just a rumor right now.