In reply to Jesse.

Dead on Jesse. Gutenberg will either usher in a new golden era for WordPress or it'll shatter it into a thousand forks. Automattic has bet the house on Gutenberg. Problem is, they're the ones with nothing to lose. They will be fine regardless of the outcome. It's the community who will feel the burden of this.

Here's my opinion: The desire to build Gutenberg is being driven by Calypso. The largest hurdle Automattic has faced with Calypso is the lack of compatibility with plugins. I think Gutenberg is a trojan horse to get plugins to be compatible with Calypso. If a plugin has to be rewritten in React for Gutenberg, it will de facto become compatible with Calypso. It explains why they're dead set on building Gutenberg in React. It explains the haziness on the future of metaboxes.