This is normal, especially for this time of year. Any item shipped bare metal, is prone to rusting. Temperature differences throughout the shipping process will create condensation on the metal that will then form a bit of rust. This rust is just simple surface rust. It can be wire-wheeled off, or it can be media blasted off. The media blasting, or sandblasting is done when someone is powder coating metal. But I suppose you could have it done just to paint them.
I don't think mine had much in the way of rust on mine, but I rubbed them down with acetone, used self etching primer, then painted them.
Next bare metal I get, I might go the POR-15 route, then paint over that.