I make a guess it will be for PSP or PS3.

PS2 or PSP

PS2/Wii

PS3 obviously.

PSP probably not - imho they will first try milking this machine with remakes.

That leaves PS2, PS3 or Wii so most probably ps3.

PS2 or 360

PS3 probably.

It's time to Atlus to enter the new-gen, i don't remember any game of atlus for ps3,360 or wii. But, PSP still selling awsome software in Japan but terrible worldwide, and Persona is some kind big in US(it sells pretty well for a non-SE jrpg). 360 proved can sell jrpg in US, its much better than before, but still not good in Japan. Wii do can sell jrpg in Japan, but still pretty week in the genre in US. So ps3 exclusive or 360/ps3 would be the best option for Atlus in my opinion.

PSP,PS3,or Wii exclusive, in that order from highest to lowest chance

I think a Star Ocean Fiasco should be avoided and they should look for PS3/PsP as their venue