Trying to have them stay on PS3 only doesn't work as well as having them go portable, or staying on the PS2 it appears.  Outside of WKC in Japan, exactly what JRPGs have done well on the PS3?

I wouldn't be surprised if the next one is on the ps2 lol

Best choice would be psp I think. No high development costs, which is a good thing for Atlus and the platform is very popular among hardcore japanese gamers. They could go HD and aim western audiences, but that would cost a lot and it doesn´t mean people would buy P5, no matter how good it is, it´s a JRPG after all. If it fails then Atlus would close down most likely, so best choice is PSP and afterwards Wii. They could also make it on HD consoles and keep development costs low without changing much technically and graphically, like Nippon Ichi did with Disgaea 3.

the difference between that game on the original xbox and rpg's now on the 360, is that for 1 thing is they actually can sell on the platform which no one thought was even possible, and that theory has been proven wrong many times over. also if the next shin megami tensei were to come to the 360 as a exclusive or a timed one, it wouldnt hurt atlus at all. the reason is most likely m$ would have paid for the developement of the game , in which case this would mean that what ever the game would sell . would be a profit for them , since it didnt cost them anything to make the game, also m$ knows how to advertise their games, and i am sure a bundle of the next game would sell quite well for atlus and m$. so its a possiblity , but i think it will go multiplatform though.

Next one is Wii or portable.

These games dont sell on ANY console. Higher production costs will only hurt the developors no reason for them to go HD.

I know what you're saying, but that's exaclty it, I'm not demanding exclusives(though it'd be nice), I'm just saying the games that SE released on the 360 would've seen much better sales on the PS3, I'm sure that many people who bought a PS3, myself included, were waiting for big next-gen RPGs to start coming out on it yet all we got was:
Folklore(good game, but it felt more like an experimental game) which was terribly overlooked by many people
Disgaea 3 which in itself is a good game, but I don't think there are many fans of that kind of genre(especially to pay 60$ for a 2D sprite game)
Eternal Sonata, I haven't played it yet(played the demo), and, although it looks great, it still felt like a last gen RPG
Valkyria Chronicles, which in my opinion is one of the best games I've played this gen, but once again it is overlooked for its artstyle and gameplay

Back when the PS2 dominated it was known as the RPG machine and many of those who bought a PS3 more than likely wanted the same, then M$ comes along and sweeps all those RPGs only to end up with low sales. Look at WKC, it alone (in it's first 3 weeks in Japan) virtually outsold every SE RPG on the 360, when it's released in EU and the US, it will more than likely reach 1 million sales. Like I said I'm not asking for exclusives.... Just give us RPGs!!! ;_;

PSP, Wii, or both.

     Well, a lot of people bought the N64 because they thought they were going to be getting rpgs from Square on a big SGI wondermachine as well.

No! haven't developers learned already? RPGs on xbox = very low sales.

The only viable way for RPG to be profitable on HD console is to go multiplat or get money from MS, its just too much for too little gain otherwise.