The swetting does not particularly have a direct relation to rich or lean. It does have more of a relation to ambient weather and velocity within the intake.
When the velocity and atomization is high in the intake, it lowers the temperature of the incoming charge. When the charge in the ports is a lower temperature than the DEW POINT of the external (ambient) temperature it then forms moisture. Moisture or condensation from the high humidity ambient air forms on the intake. Much like taking your favorite cold soda out on a warm summer day. Cold on the inside and condensation forming on the outside.
All in all I think it is a good thing...