I think Ford made a calculation, and realized that the cost of running a separate manufacturing facility to produce a truck with low sales volume was a losing proposition. Ford figured that they would capture some of the Ranger sales in folks moving up to the F150, and other sales would move from Ranger to Ford's inexpensive compact and subcompact cars. Losing sales to the Tacoma was inevitable, but overall it's better for Ford to sell F150s than Rangers (in USA, at least).
Here's a look at the Ranger Ford builds for the rest of the world. Ford could still import these as knock down kits (the way Mercedes imports Sprinters) from Thailand or Argentina if they wanted to.
http://www.motortrend.com/roadtests...l_market_ford_ranger_first_drive/viewall.html
According to this article, the Ranger is a couple of inches smaller than an F150 in all dimensions
"overall length (F150 231.9 inches versus Ranger 210.6 inches)
wheelbase (144.5 versus 126.8)
track (67 versus 61)
height (76.2 versus 71.7)
bed length (67.0 versus 61.4 inches)
distance between wheelhouses (50.0 versus 44.8)."
The Ranger has a cargo capacity of 2200 lb.
The Ranger's 3.2 5 cylinder turbodiesel puts out 345 ft lb, and can tow 7400 lb. This engine will be used in the new full size Transit van. I expect the diesel will be available in the F150 in a couple of years.
Ford has improved fuel economy in its best selling F150. But the company needs to do more to meet the 2025 CAFE target. We'll know more about how Ford plans to do this when we see the all-new F150 in 2014.
Personally, I think all the pickup truck manufacturers are making a mistake by continuing to style their half ton models like miniature Peterbilts.