There seem to be more Metal Gear Rising skins in the works. This was announced on the PlayStation Blog by the social media manager of Konami, Dalton Link:
We don’t have the MGS2 Raiden Skull Suit planned for MGR at this time, but there are some AWESOME Raiden exoskeleton armor varieties in the works!
When someone asked if the game would be available through PSN, he answered:
We’ll make the announcement on the digital release of MGR soon! Please stay tuned!
As stated, more information will follow at a later date.
Source: PlayStation Blog