The new automatics may get better gas mileage but they are also becoming more and more complicated and more expensive to fix. On top of that some require speciality fluids that are available only at the dealer.
For me concentrating is not an issue with either configuration, but I think a lot of people would drive better if they learned how to drive on the manual first, as it requires much more concentration from a new driver that learns how to shift and therefore they learn to look far ahead and try to anticipate traffic conditions.
My wife, for example, never drove a car with a manual transmission and she never looks more than 100-150 meters in front of her, it irritates me to no end when I see a red light ahead and she is still on the gas, and waiting to brake to the last minute, she just doesn't get the concept of coasting to the red light. Same thing on the highway, when the traffic slows down, usually letting off the gas is enough, provided you don't tail gate, but my wife has to step on the brakes, usually slows down too much and then has to accelarete, rinse and repeat, and the gas mileage proves the inefficient driving, as she will always get worse gas mileage than I do, even on long trips with same speeds driven.