Sure, full suspension on a bike is nice but the first place you should absorb shock is at the tire. Traditional bike tires aren't that good at absorbing shock. The fixed composite or spoke rims aren't made to absorb bumps, so that job was handled by the air filled rubber tire. Just like a car with low profile tires, the ride is rough.
The folks at LoopWheels have a solution. LoopWheels ($775) are 20-inch bicycle wheels that have a built in spring system to cushion your ride. Currently the deal is on Kickstarter and should ship August 2013. Video of the LoopWheels in action after the break.