THe multiple sticksets have been implemented from the start AFAIK. You need to do two things, fist map all your keys in all the sticksets you plan to use in the Joystick Mapping section under Setup. Second, map keys to switch between sticksets. You can find the mapping for switching sticksets in the Global section of the Keyboard Mapping and Joystick Mapping sections under Setup.
So basically, you can have 1 setup for say all .50 cal planes, another for cannon/MG combo birds, another for dive bombing, and another for level bombing in BUFFS. It's very cool.