He sagte as much in an interview he did in London while promoting My World 2.0. Basically he sagte that it depends on the situation, but that he would do it. Justin isn't only up for dating other stars, he would datum anyone if she was the right sort of girl.
And another detail: Justin likes girls with nice smiles, pretty eyes and who can make him laugh. This is his Beschreibung of his dream girl. Do Du fit the mold? The Du may be just right for Justin!