Hi folks! Thanks for Cc:'ing me into this conversation, because I'm interested in seeing where others are going.
I don't have time to contribute to the conversation myself because I'm busy with the Least-Authority File System project (https://tahoe-lafs.org). I think and hope that LAFS could be a useful building block for some of the purposes that you folks are talking about. I'm about to announce a commercially-supported LAFS service for people who would rather pay my company than operate the server software themselves. We've contributed all of the code that we wrote for this commercial service back to the Free and Open codebase at https://tahoe-lafs.org. Regards, Zooko
