Ha. Nah that's just my experiment. I plan to use the SpaceMouse in just 4 Axis configuration and use the superior mouse. Only when looking arround will I probably use all 6.
People already tried Joysticks and Gamepads. It worked but everyone said it's harder to controll then with the mouse, which we anticipated, didn't we.
The Input Mapper Flavien made is really solid. You can add whatever axis you want. It also seems to have the option of using two analogue input devices simultaniously, although the launcher only allows for one at the moment. In the meantime there are 3rd Party tools that allow you to combine Joysticks.