This concept (from NASA and Cal Poly San Luis Obispo) is called AMELIA, which stands for Advanced Model for Extreme Lift and Improved Aeroacoustics. There are two relevant bits there: "extreme lift" and "improved aeroacoustics," and both of these things come from mounting jet engines on top of the aircraft's wing instead of underneath.
Let's start with the extreme lift. With the engines up above the wings, their exhaust is directed over the wing's upper surface, creating what's called a "circulation control wing." As the high pressure exhaust flows over the trailing edge of the wing (back where the flaps are), it wraps around and downwards, generating a bunch of extra lift through a phenomenon called the Coandă Effect.
At the same time, the fast-moving exhaust above the wing increases conventional airfoil lift. Put all this bonus lift together, and estimates suggest that an aircraft like a 737 could have its landing lift coefficient increased by up to 250%, reducing approach speeds by almost 50% and landing distances by 75%.
Noise reduction with this deign is much simpler to explain. With the engines above the wings, the wings block a bunch of engine noise from reaching the ground. And since you've got all that extra lift to play with, aircraft can make steeper approaches and climb-outs to spend less time near the ground.
The upshot of all this is that with a blown lift design, passenger jets could potentially access the small regional airports that are scattered all over the country. It would be easier for you, cheaper for the airlines, and would help take some of the pressure off of overcrowded international airports. And as far as concepts go, this one is very realistic. NASA already has flying examples of blown lift configurations, like their Quiet Short-Haul Research Aircraft, which can land and take off from an aircraft carrier without arresting gear or catapults:
The other way to look at this tech is that instead of getting big jets to land at small airports, you could keep big jets at big airports but drastically reduce the size of their wings. Wings are great for landing and taking off, but after that, most of what they do is cause drag, which is the idea behind aircraft like the F-14 Tomcat and the B-1 Lancer: the wings swing out at low speeds, and then swing back into a delta shape for supersonic flight. Being able to reduce wing size means both faster top speeds and increased efficiency, which hypothetically translates into shorter trips and cheaper tickets for people like us. LINK
Paper (PDF), via Aviation Week
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