Loopwheels' funding campaign runs on Kickstarter through May 15, 2013. Backer packages range from a single front or rear wheel to both wheels to a Dahon folding bike pre-pimped with its own set of 3-speed Loopwheels.
With all the comfort that the Loopwheels provided I was concerned about the responsiveness of the bike – but my worries were for naught, as soon as power is applied through the pedals the bike skips forward without any noticeable lag (I’m smiling just writing this)

The gantry was to work by building a framework, with rails constructed from 1x1 blocks. The gantry X/Y axis arms are to traverse the rails with wheels. There would then be some pistons for the z axis, a rotor, and finally a landing gear for grabbing. All pretty straightforward stuff. On something like this, you do not want suspension on the wheels:
In deep sand and mud conditions, TRX uses a 45/55 initial torque split and calibrates both throttle management and torque distribution to mitigate wheel slip and improve traction.