Samsung told me that it sold out of the 470 series OEM SSDs late last year and the company only makes a much faster variety: the 830 series.
How fast is the 830 Series controller/chips? I had a chance to speed test the popular 2.5-inch 830 model late last year when it debuted. Typical speeds were over 400MB/s write and 500MB/s reads (below, left). That is almost twice as fast as the current MacBook Air SSD from Samsung (below, right), which itself is significantly faster than Toshibas SSD.
Samsung stopped short of announcing it is shipping the 830s to Apple, but the company confirmed it ran out of 470s a while ago and all of its SSD customers were receiving the updated 830 series. Samsung also confirmed that Apple is still a customer.
http://9to5mac.com/2012/01/11/the-macbook-air-samsung-ssd-is-about-to-get-twice-as-fast