AeroMexico flying to ORD? Great! Another new route. I think they'll use 757s, that's the most convenient type for a MEX-ORD.
Mexicana has a lot of flights out of ORD to cities such as: Mexico City, Guadalajara, Puerto Vallarta, Zacatecas, Leon and Monterrey. Both AA and UA fly ORD-MEX, and AA has a Chicago-Los Cabos flight.
By the way, AeroMexico just started flying Atlanta-Cozumel with MD-80 aircraft.
"... for there you have been and there you will long to return."