This is useful info and should really, really be in the FAQ. Like, right at the top, because I don't think it's clear right now at all what happens to regular domain holders using them for email, their own services, intranets and so forth. If those in the current registrar system have a
reliable path to transition/try it out at some point that's a good start.
Edit to add: your namebase.io FAQ seems a lot more useful than the handshake one. For starters it clarifies that there is a confusing terminology difference, where I guess the handshake people are using "domain" to mean "TLD" and "subdomain" to refer to what everyone typically calls a domain. So a core offering of this system appears to be a blockchain based replacement to the $150k+ (or whatever it is these days) "get your own arbitrary TLD" thing ICANN did, "anyone" gets to register their own TLD. But that raises more questions, like where the actual hardware behind all this goes particularly for existing TLDs which are blacklisted.