In a recent interview, Takashi Yuda (KNUCKLES'S craetor) hinted, that KNUCKLES and Rouge will appear in the upcoming Riders 2 (Xbox 360, PS3) as a couple.
=== Shadow===
Rouge has a connection to Shadow the Hedgehog. They are teammates in Sonic Adventure 2 and Sonic Heroes, and often work together. Whether the feelings between Shadow and Rouge are romantic or platonic is an opinionated conclusion.
In Sonic Battle, Rouge calls Shadow "not bad-looking" and "a prince," and also lets him live with her when he lacks a place to stay. Moreover, in Sonic Adventure 2, Shadow saved her life when she was trapped in Security Hall. He later claimed he was just saving the Chaos Emeralds she had with her, however he might have said this only because he felt embarrassed of her remark about how impressive and unexpected it was for him to come back and rescue her.
In Sonic X, when she first established the business transactions for helping Eggman and Shadow find the Chaos Emeralds, she seemed oddly interested in Shadow. However, she was interested in him only because of his close resemblance to Sonic and later finding out the he was the main part of her mission: to find out whether or not the claims of his being the "Ultimate Life Form" were true. Also, once when Knuckles questioned if Rouge was in contact with Shadow, she responded, "Does that make you jealous?" However, since she was not being serious, this was not indicative of a developing love triangle. Also, there are rumors that the Sonic the Hedgehog official guide book states that Rouge has feelings for Shadow the Hedgehog in her profile.
In Sonic the Hedeghog, she tells Shadow that even should the entire world turn against him, she'd stay by his side no matter what.
In Sonic Rivals, the ending for Shadow's storyline also showed that Rouge and him have a close bond together.
