We would have more Lagrange points in the earth-moons system. This would mean more spots for potential telescopes and/or space stations. We would have less stable tides. Greater third-body perturbations on high-Earth satellite orbits could cause them to be less stable. Something about women's cycles may be different...not sure what. We'd have a scientific theory about how the two moons formed. Undoubtedly a story in all ancient texts about how the two moons got there. And we'd have a pretty sweet night sky, though it would have more light pollution and the stars and our galaxy would be more difficult to see with the naked eye.