Yeah I expect them to do that. The problem is that since the game is a port those advancement will only interest a very few minority of people (or even notice those changes) and because only early adopters are going to buy those games, all those 10m+ players are going to stay with the PS3 or 360 version.

So I honestly don't see the new version taking off. And thus begins the problem the OP is saying. 

We will...from eastern Developers.Especially from those who still develop JApanese Games for the Japanese Community(not SquareEnix and Crapcom)

This time they won't support the new Xbox.They will either go WiiU or PS4 Exclusive.
There is no reason to believe in Microsoft again for them.They had the best support you could get in this Gen in the first few years and couldn't do
anything with it.Most studios even had more problems than before till Sony saved them.And we came from a Gen where J-RPGs where what FPS are now.They had money and couldn't do the jump into the NextGen without any problems and help.
If developing on NextGen is more expensive than in this one they have to make a big choice.
Go for the money Microsoft is offering them and sell like 40k units or go Sony/Nintendo Only.Cause with those 2 you can even sell your games in the west as the community showed in this Gen with petitions and big crying.

I think a lot of the early games will be a crazy mesh of Ps3 / 360 / Ps4 / 720 multiplats, maybe even with a Wii-U port if people start bothering with that. Obviously all the EA sports games will, COD will, Battlefield 4 etc and whatever else. But don't be fooled the Ps4 / 720 games will still be superior for graphics, online and whatever else and thats a big selling point for many people in general.

HOWEVER, I'm confident all the third parties will be launching exclusive games on the new consoles too - whether they be new IP's akin to what Assassin's Creed was or existing games. Why? Because third parties are competiting with each other for marketshare more so then anything, and whatever game gets hyped as the true 'next gen' thing could explode like AC or COD. Every publishers gonna be under pressure to put out a game that truly explodes on the next generation consoles - I'm actually expecting a glut of new IP's so kind of excited. Throw in the first party stuff and you're sorted.

Just raise the price for PS4/Xbox³ games to $70 and third parties will try to push the new consoles, which wouldn't even be unfair since that would correspond exactly with the inflation rate.

On the other hand, that could be a big boon for Wii U, if 3rd parties stick around on PS360 longer, Wii U is much more likely to stay in the loop (if 3rd parties manage to get their heads out of their collective ass, which admittedly is iffy)

Raising the prices will be even worse. People will have to buy a $400+ console and a $70 game. It doesn't matter if the games looks like Avatar, most people will not throw that much cash for a single game. Especially if you can buy the same game (only with "uglier" graphics) for only $60 with a console you already own, plus all your friends will be on the PS360. 

Do Sony/MS set the price cap then?

If third parties go PS4/X720 too early we will see even more blood than with PS3/X360, because dev costs will be even higher and this time making games like Carnival Games on the Wii to make money won't be an option.

What they can do is to make a PS3/X360 versions, and we'll see what effect does that have on the PS4 and X720 sales because the bestselling games in Sony and Microsoft consoles are third party games.

Hm I don't think so.

http://www.destructoid.com/kotick-i-would-raise-game-prices-higher-if-i-could-143049.phtml

or should I say at least Activision doesn't think so ? ^^

No that's the decision of the third parties. If they would like you to buy the $70 version they will try to lure you by either giving the $70 game more content OR decrease the quality of the $60 by a bit and with that I'm not only talking about worse graphics.