Since the early days of Wagtail, native multi-language support has been one of the most-requested features, and perhaps the one that has held people back the most from adopting Wagtail. With the release of Wagtail 2.11, it's here at last...
Add-on packages Wagtailtrans and wagtail-modeltranslation have filled the gap in Wagtail's multi-language support, and served as the inspiration for the new implementation. Wagtail 2.11 introduces a number of changes to the page model, including the addition of a 'locale' field - for upgrading users these changes should be largely invisible (although there is a recommended fix for migrations to ensure that new deployments can be brought up cleanly). A new package wagtail-localize provides the user interface for managing translations, with possibilities for integrating machine translation and external translation platforms such as Mozilla's Pontoon.
This release also brings improved image and document management, allowing collections to be nested. This will be expanded further in the upcoming 2.12 release with the ability to set 'choose' permissions on collections, paving the way for multi-tenant setups where user groups can manage media independently of other groups.
Another compelling reason to upgrade is one that's unfortunately out of our hands: YouTube has recently made changes to their oEmbed endpoint to enforce HTTPS, which has led to video embeds on older Wagtail versions failing with the error "Cannot find an embed for this URL". This is addressed in the new release - alternatively, if you're not able to upgrade yet, this can be fixed through a patch to your settings file.
For the full lowdown on the changes, see the 2.11 release notes.
Wagtail 2.11 is a Long Term Support (LTS) release, and will be supported with security updates for an extended period lasting until February 2022.