Although it servers an entirely different purpose, there are a couple of things I would ask:
1) How would one share encrypted files?
2) What happen when user forgot password?
3) What cryptographic algorithm is this using?
Actual issues when I gave it a try: 1) Unmounting the safe is possible but there's no easy way to remount the Safe 2) All the filenames are obfuscated (good and bad). Abilities to search for files, view thumbnails etc., usual filesystem functionalities are affected.
I think it's quite early but it is an intriguing project. Like others, I would love to learn more about the folks behind it as well as the product details.
I wrote a little bit about data security, especially cloud data security a while back: http://vuongnguyen.com/personal-business-cloud-security.html if anyone is interested in my humble opinion.
-V.