Other rumors are:
Green Lantern from Six Flags Great Adventure may be coming. This will be a great choice, in my opinion. This will bring in record amounts of people to ride a coaster that is taller than some have ever ridden. Frontier City is the only amusement park in Oklahoma (besides the kiddie park) and alot of people can't afford to travel to another state for a bigger amusement/theme park.
Wildcat is getting a 2nd train soon and it will be an RMC train.
Finally, I have heard something from this year's preview day for the park, which happened on the Sunday before they opened this year. Someone said they were walking around the park with a group of people and a man that sounded like a tour guide (of sorts), talking about all the changes. They eventually got to the area where the go-karts used to be. He asked if Six Flags had any plans for the area. Besides the warehouse that was already mentioned, they are thinking about adding a wild mouse coaster to bring more people to this area of the park.