Vue creator Evan You has done a complete write up on the planned features of Vue 3

In simple terms, what are the new features of Vue 3 that you, as a developer, can use?

  1. Class-based components. Rather than declaring components with an object e.g. Vue.component("my-component", { ... }); you can (optionally) use an ES2015 class.
  2. Fragments. These are components with multiple root nodes e.g. <template><root1/><root2/></template>
  3. Portals. These are subtrees of markup that can be rendered outside of Vue’s mount element.
  4. Functional components as plain functions. Not sure of the syntax yet, but maybe something like function myComp(h) => h("div", "Hello, World");
  5. Improved reactivity. By utilizing ES2015, Vue 3 will eliminate current reactivity limitations. By utilizing new ES2015 features, Vue 3 will eliminate the current reactivity limitations i.e. will be able to detect any kind of object or array mutation and new data types like Maps and Sets can be reactive.
  6. TypeScript support. For example, you’ll be able to use TSX for render functions (JSX in TypeScript files).