The article below about top IC foundries ranks from 2010 through 2012 documents Samsung's improved foundry position. The improvement was mainly due to Samsung's complex relationship with Apple.
Samsung is trying to diversify away from Apple (see Samsung Foundry Replacing Apple)
Insightful, timely, and accurate semiconductor consulting.
Samsung Jumps to #3 in 2012 Foundry Ranking, Has Sights Set on #2 Spot in 2013