They say that 80% of what makes a great wine is what happens in the vineyard. Eastern Washington has perhaps the most perfect climate in the world for growing Bordeaux varietals such as cabernet sauvignon, merlot and cab franc. They are at the same latitude as Bordeaux so the extra sunlight in the summer time growing season helps ripen the fruit, while the cool nights (down into the 50s during the summer) help the fruit to rest and lead to wonderful acid balance. Because the entire wine region is in the rain shadow of the Cascade mountain range, the average annual rainfall is about 6-8 inches (unlike Seattle, which has a maritime climate that would be disastrous for grape growing).
On top of the climate, Eastern Washington also has two other things going for it -- soil with good drainage (important for keeping grapes from becoming waterlogged -- you want grapes that are small and intensely flavored) and access to an excellent irrigation network, which exists because eastern Washington has been agricultural for so long and because of the proximity to the Columbia River.
One other important aspect of Washington's vineyards is the relative absense of the phylloxera louse that ravaged France and destroyed almost all of its vineyards in the 1800s. (All of the vineyards of Bordeaux are planted on American rootstock, because the American rootstock is more resistant to phylloxera). There are a few theories about why the insect isn't widespread in Washington, and the prevailing theory is that the louse doesn't like Washington's sandy, loamy soils because they are well-drained. (It is just an added benefit that the well-draining soils also happen to be the ideal conditions for growing premium wine grapes.) In any event, some people think that grapes grown on their own rootstock can achieve higher quality than those planted on grafted rootstock. Whether this is true or not, I am not really sure.
As far as the use of French oak barrels, that is commonplace in Washington and everywhere else where wine is made. Although there is some debate over whether French oak or American oak is better, the fact is that most super-premium cabernet sauvignon is aged in the highest quality new French oak barrels (which run about $900 each). There are a few top cabernets aged in American oak, but French is the far more popular choice. For other varietals, however, such as syrah/shiraz or Zinfandel, American oak is the more popular choice because the flavors imparted to the wine marry better with those particular varietals.
Its remarkable that a winery out of Washington is able to deliver a cabernet sauvignon as well, if not better, than a Bordeaux winery. I imagine that it comes from a combination of cross-polinating knowledge and resources, and experimenting with recipes. I also have a feeling that its quite the exact science, and have heard that winerys like Quilceda Creek actually import wood from places like Bordeaux for their barrels, so as to achieve the flavour and aroma of an authentic French caberenet sauvignon.