A very good thing, but will not accomplish as much as many people think.
Oil prices, and therefore gasoline prices, are determined by the world market, not the US market. Since nat gas is usually distributed by pipeline, it's somewhat isolated from world energy prices.
So while producing all our oil in North America doesn't necessarily mean gasoline prices will go down, it does mean OPEC can't turn off the tap.
It will help drive world energy prices down, it will begin to neuter the middle east as energy king, disenfranchise the new muslim brotherhood nations, and begin to transform our economy into gas driven rather than oil driven. It's carbon neutral to boot, so the greens are (for the moment) neutralized! That's a huge change, one that will bring new industry, the car companies are all racing to develop this new resource under the radar, competing with each other to the first and best. They are shipping this overseas as well, by tankers.
Trust me, I understand that if anyone could f this up, it's our current administration, but this is for real, and it's not going away.