Gutenberg 3.4 was recently released with “a multitude of improvements when converting existing content to blocks,” a REST API search controller, additional documentation, and more than a dozen bug fixes.
Gary Pendergast also shared a sample plugin on Github that shows how to convert existing shortcodes into shiny new Gutenberg blocks.
Brady Vercher has created a Gutenberg block for editing and displaying code with syntax highlighting.
Easy Digital Downloads is creating Gutenberg blocks and has a Github repo for their latest work on the EDD Blocks plugin.
Spencer Green wrote about Gutenberg and compatibility with Advanced Custom Fields. If you are on the latest version of ACF, Spencer says there should be no problems with Gutenberg being used. However, that doesn’t mean you shouldn’t start testing now — and make sure all your non-Gutenberg plugins are updated too.
There is an official page devoted to Gutenberg on WordPress.org now, complete with an (almost) fully functional demo of Gutenberg. This page is primarily for the public, and it’s already been effective from my observations in communicating what Gutenberg is and how it works to those who are learning about it for the first time.