From the release notes:
The most concerning issues and improvements from the community have been addressed, including:
- Node instantiation performance enhancement
- Spine and DragonBones animation supports mesh rendering
- UI label enhancement, including LabelAtlas support, bitmap font batch rendering (batch with other sprites!), rich text strokes, etc.
- Extension store is online, more editor extension interface is supported
- Include a lot of hot update issue fix and interface improvements
- Add third party library to handle audio soft decoding on android, to improve compatibility and performance
- Added VS Code debugging web platform workflow support
The full announcement goes into a great deal more detail about the new functionality in this release.