So.... I just saw this on IGN.
Apparently the article states that Atlus may be bringing over the PS2 version as a direct emulation via PS2 classics. Persona 3 FES is already up on PSN so this doesn't seem like an entirely out there idea. So hey, if you want to play some persona 4 on your PS3 and don't have a backwards compatible system I guess now you probably can do that soon.