https://github.com/reactjs/rfcs/blob/createlement-rfc/text/0000-create-element-changes.md

Major changes for us:

• JSX children are always installed as an array on the props object - not as trailing arguments.
• key will be passed separately from other props (in place of children)

Also of note:

• defaultProps will be deprecated on function components
• Spreading key will be deprecated
• String refs will be deprecated

We might need new jsx flags, or jsxFactory flags, or something similar. Checking might need to be changed to reflect this as well depending on if/how we resolve createElement calls.