It is generally agreed upon that oil production follows a bell curve.
Oil is increasingly plentiful on the upslope of the bell curve, increasingly scarce and expensive on the down slope.
The peak of the curve coincides with the point at which the oil has been 50 percent depleted.
Therefore, oil will not just "run out" immediately but will become increasingly scarce.
This is true whether we're talking about an individual field, a country, or on the planet as a whole. Many projections of Peak Oil have it within the past five years and once the peak is passed, oil production begins to go down while cost begins to go up.
Currently demand for oil is lowered due to the worldwide economic downturn.
The issue is not one of "running out" but rather not having enough to keep our economy running. An oil based economy such as ours doesn't need to deplete its entire reserve of oil before it begins to collapse.
A shortfall between demand and supply as little as 10 to 15 percent is enough to detrimentally impact an oil-dependent economy.