Responding to a Formspring question about a potential port to Nintendo's 3DS hand-held, The Binding of Isaac, co-creator Edmund McMillen revealed that discussions are already underway. In responding to the question, McMillen revealed that "a publisher I know is currently asking Nintendo if they would be OK with Isaac on the 3DS." If Nintendo approves of the game being on the platform, he said that he is willing to "let them port it."
McMillen added that the 3DS was the "only other system you might ever see Isaac on."
Due to the graphic adult subject matter and violence in the game, a port might be difficult to get on the mostly kid-friendly Nintendo hand-held. Still, it would be in Nintendo’s best interest to start thinking outside the box when it comes to game content. It's also surprising that the game has not been ported to Xbox Live Arcade or PlayStation Network, but maybe it's subject matter is a tough sell to platform holders as well.
On a related note, the game is on sale at Steam right now for the next three hours. It's priced at less than $2.