This is super exciting -- Public DNS space frankly needs more entrants.
I've been a long time user of OpenDNS's public DNS service (and have come to adore it greatly). Other recent new entrant to this space worth mentioning includes Global Cyber Alliance's [0] Quad9 DNS service, launched in Q4 2017.
This to me looks like a good move by Cloudflare, business model wise, given the increasing awareness among general public to the dangers of privacy breaches -- aside from the supposed boost in network speed piggybacking off of Cloudflare's extensive server farm network [1].
Whether the service delivers on it's bold claims, however, is to be seen. I'm going to go give this a shot now.
[0] https://www.globalcyberalliance.org/initiatives/quad9.html [1] https://www.cloudflare.com/network/