Gutenberg version 2.2 has been released on 16th Feb 2018. You may check out the announcement post and read through the changelog to understand what has been updated.
Gutenberg version 2.2 changelog is huge, here are some most noticeable highlights.
Block Nesting ?
Block Nesting is live!
It comes with an experimental Columns block. (Note: converting a nested block into a reusable block is disabled on this first version.) Furthermore, this is not a specific implementation for columns alone — any block author can take advantage of defining nested areas.
This is HUGE. This by default comes with a new column block for now (which is highly experimental in this release). In simple words, users can now expect to create multi-column complex layouts using Gutenberg Editor (not just now, but soon). And this is just the beginning, there is a lot planned to come related to the implementation of the nested block. For example, you can expect a Section Block – Which will allow you to have a group of content where you can add a background image/color. And a lot more to follow.
Refined block insertion experience
Introduce block shortcuts on every empty paragraph block. This also temporarily disables the sibling inserter as we work on refining this interaction.
Add trailing text area at the bottom of a post to continue writing.
Now you don’t get different (+) block inserters as earlier, but only one at the top. And also each new/empty paragraph block will show three recently used blocks and the (+) block inserter.
This is experimentation change for now, and the team is gathering feedback on this. Be sure to pass your feedback here.
Preview Saved Blocks
Preview saved blocks while hovering on the inserter. Allows users to quickly see what they are inserting before inserting.
This is a great feature IMO. When you will start using the new WordPress editor on product sites soon. You will end up saving many reusable block/group of block (hopefully). As the saved blocks were only showing you the name which is fine if you have a couple of saved blocks which you can remember. But with many blocks saved to your blocks library, that was not cool. But now with this feature addition, you get a nice preview of your saved block(s) instantly when you mouse hover over it. So you can preview it before you insert it.
Developers: Noticeable Updates in Gutenberg 2.2.
There are updates to the Block API, new props, components, filters & attributes added. Read the full changelog for details. Each an every bit of the changelog is noticeable for developers in version 2.2. A highlight would be the addition of Inner blocks.
InnerBlocks.Content components added, which can be used by block implementers to edit and save nested blocks, respectively. See documentation.
Read more about it on this issue.
But there is a lot more besides that and you must go through the changelog and all the issues closed for v2.2 at GitHub to keep you updated with all the API changes.