One of the most valuable aspects of owning & developing on googles devices/platforms is the fact that it's completely open. While rooting may not appeal to some users I hate to see posts about how Google is "locking" or "forcing" users to exclusively subscribe to their services when in reality they are among the only platforms that remain completely open and backed by a gigantic open source community that make a pure google device have far more advantages than just the technical specs or other platforms have to offer. ANYWAY..
See this article.. OR search for other devices that did not support usb storage out of the box - Its been done before. http://liliputing.com/2012/06/google-nexus-7-hacking-begins-root-custom-recovery-system-dump-more.html