Soon enough Apple will design their own NAND & DRAM and be 100% free of Samsung. That's what the purchase of Anobit was about. Apple will do 100% of their own component designs for mobile devices by 2015-2016 and 100% of component design for Macbooks by 2018. They will remain fab-less, but by eliminating the middle-man component designer that will increase their control and profits.
Anobit doesn't make or design NAND. They make SSD controllers and concentrante on improving endurance of NAND.
Designing SoCs makes some sense because it allow customization but you can't customize NAND or DRAM, it's all the same. Why should Apple spend even a penny on designing that stuff? They can already buy it from numerous suppliers.
Fab-less means they would still depend on others. Actually, it might worsen their position. Now, when a new process node is released, Apple can buy the chips based on that. However, without their own fab they would have to wait for the manufacturer to manufacture their own chips first. Samsung wouldn't start with Apple chips, they would start with their own.
Besides, as stated above, who would manufacture the stuff? NAND and DRAM are low profit products due to high competition, why should Apple enter that? A consumer won't care what's inside his phone. Oh, right, he doesn't even know.