According to the linked article, Toyota expects to have every vehicle in its lineup be hybrid by 2020. The reason is that the company's research has found that"cost cutting on the electric motor, battery and inverter were all showing positive results", so that "by the time Toyota’s sales goal of one million hybrids annually is reached, it “expect margins to be equal to gasoline cars”. According to Toyota, hybrids will be competitive with diesel engines because "diesel vehicles, as favored by the European carmakers, require expensive particulate filters and other traps that cost almost as much as the first generation hybrid technology."
This would lead to a significant drop in gasoline demand by Toyota drivers; given Toyota's global market share the resulting impact in fuel consumption would be meaningful.
Here are some additional links from the article: