Its something like that. Sony own the rights to publish the game outside of JP(EDIT).
If it is just a remake, they will have the rights to the publishing and distribution of the title outside of japan.
If it's a new game, they will not. For instance, EPIC games cannot remake gears of war 2 with enhanced PS3 graphics and release it anywhere in the world Microsoft game studios purchased the rights to publish the title.
The game, the IP and all the content inside it belong to Sony outside of Japan. Multiplatform will NOT get the game substantially more sales. Infact, I still stand by my beliefs that making 13 multi-platform lowered sales of the title. They certainly lost my purchase, for instance. Not many 360 owners will buy the game. less than 600,000 I assume.