Even with the growth of thin client mobile devices such as tablet computers and smart phones and the use of content only borrowed from the web rather than copied our total storage requirements are growing.
There are so many things that can slow web apps down, and even if you cache and optimize your data feeds, move the heavy lifting from the server to the client and all of the other things that smart app developers have been doing, you still will bump into the limitations of the browser.
Thin client (lower storage capacity and processing power) products such as smart phones and tablets would greatly benefit from the larger storage capacity that 20 nm NAND flash will provide.