"Tight Oil" and the
Bakken ShaleColes notes version: Tight oil is basically the petroleum equivalent of shale gas, which already carried the possibility of rewriting the world's energy supply balance. The most optimistic projections would have the US weaned entirely off non-North American oil sources by 2015. This is unlikely, but even low projections show the US may have found a very significant new domestic source of oil, which would go a long way toward stimulating the domestic economy and reducing trade imbalances.
When you boil it down, shale gas and shale oil are just the small pockets we would have ignored historically, because giant oil strikes were much easier to tap. So who know what the really long-term viability of this is. Could be boost for domestic production that lasts a mere 20 years, or it could last 100. The strikes are all collections of small pockets, so variability of finds is much wider.
The down sides here is that like shale gas, much (but not all) of this stuff has to be obtained through fracking, which carries the danger of earthquakes, ruined water tables, and having your oil well mistaken for a set for a sci-fi TV show.
This could get interesting (Thad, if this generates much discussion, feel free to move it to Death Panel land).