REST APIs have been the state of the art for many years now. Martijn Walraven (author of apollo-ios) gives an excellent overview why he thinks that GraphQL will replace REST. He especially highlights one of GraphQL's superpowers: Types.
Querying nested data structures has become almost trivial with GraphQL whereas creating nested data is often still tricky. Graphcool now introduced nested mutations to create related nodes in a single mutation.
This article contains some really interesting thoughts on how GraphQL could be the foundation for a better way of integrating different services. The new GraphQL API of Github is a perfect example of that.
Content management systems have learned their lessons and evolved a lot over the last few months morphing into "headless" backends. Drupal 8 now added support for GraphQL which makes it an interesting choice to build static sites powered by GraphQL.
Another milestone for GraphQL: Apollo hosts the first one-day conference of GraphQL and invited speakers from Facebook, Spotify, Github and many other companies. The early bird tickets are already sold out.