For comparison, WolframAlpha states that the average strand of human hair is 80 micrometers thick, while a US dollar bill is over 100 micrometers – so they're some mighty slim chips to say the least.
The new NAND memory is aimed at a wide range of consumer goods, such as smartphones, tablet PCs, and digital video cameras. No buyers have been named, but you can expect Apple to make it to that list at some point, being the largest customer of flash memory.
Samples of the 128GB product are expected ship by September and full-blown production should begin in the fourth quarter. A 64GB chip built with the same technology will begin sampling a bit earlier in August, but it will enter mass production along with the 128GB variant.