Wow. Talk about instantly seeing the future... Not just the layout-but seeing airliners for what they are: Overgrown buses. Additionally...I would speculate that the near-term doubling of air traffic will come from the increasing number of "air taxi / limo" services that will pop up to service those that can afford not to be herded on to these beasts.Couple that with the realization of a functional / stylish "flying car" for those who can afford the convenience...and you have what I call: "The Aviation Software Coders Full Employment Act". :-)

This doesnt look like it would easily scale to changes in aircraft geometry.
People thought the A380 was extremely difficult to accommodate at conventional gate layouts. Imagine what would have happened if this sort of airport were widely employed before the A380 was conceived. Imagine what the impact would be for airports if the Boeing Blended Wing Body aircraft program eventually bears fruit.

The reason why nobody has does this in the past is when the first plane breaks down you have to tow it out delaying all the rest of the planes. Looks good on paper but really is a bad concept.

One delay to one aircraft and what happens then?

Breakdowns will probably be handled the same way they are handled today when a plane breaks down at a gate or on a runway. They tow it. There have been strongman stunts where one guy has gotten a jumbo jet moving single handed without power so I suspect that it's not an unsolvable problem. Maybe they will even have the foresight to have more than the minimum number of lanes needed.

As for the A380, not all airports are going to have the runways for them anyway. Big, transoceanic flights will likely service the biggest airports which will have some or all regular terminals while most travel can go through the lines. Lots of airports have more than one section as some are built at different periods of time.

Looking at the pictures it looks like the lines are only 3 planes long. Each plane in the line first unloads the passengers, then is serviced, and then loads the new passengers. Any delays would only have an effect on at most 2 other planes. As any other plane would be able to be redirected for entering another line. Looks good to me.

"Why hasn't someone done this before?"
Because it will work just as well as drive through lines work at your favorite fast food store. You know, like the guy who tries to figure out what he wants to eat after he stops in front of the speaker, then doesn't have enough money to pay for it. Or the kid spills his drink and wants another one.
So the plane in the rear is fully loaded, fueled and has a flight plan ready to go and the plane in front has an unruly passenger that has to be offloaded by sky marshals. Is it really that hard to see what could go wrong with this scheme?

Re DemonDuck;
Time to try the Thunderbirds concept of detachable passenger cabins, someone being a problem means removing the cabin, the flight behind can then have its passengers moved up the queue with a cabin swap.

Then there is also the confusion of having all the passengers at the same gate.