We've been waiting for this to happen for some time. Love Field, Dallas & Southwest have had to deal with "The Wright Amendment" for years. Since the big airport was built in the early '70's, I think it was.
It was a complicated law that was supposed to help the DFW airport get off the ground, by restricting flights out of Love Field to not being able to "jump" states that are immediately joining Texas. In other words, a flight out of Love can not fly to Missouri without stopping in Oklahoma first.
The Wright Amendment is slowly being phased out (finally! DFW is doing fine and is in no trouble of going out of business due to Love traffice), it will be gone by 2014, that is probobly when Southwest will go fully international.
This is great news! Southwest is a VERY well run company, it treats it's customers and more importantly, in my opinion, it's employees with great respect & they have a very good business model...unlike a certain other airline that is hubbed here in the Dallas area and is going through bankruptcy.