The version 2 of dropbox he refers to already exists, it's called JungleDisk. It works on bring your own storage (S3 and now few others), and you get to keep your own crypto key. It added sync while back.
Been using it for few years, since I was not that comfortable put all my files in the cloud.
Been using it for few years, since I was not that comfortable put all my files in the cloud.