Currently only the role (ariaRole) attribute is supported in Ember core components. Various WAI-ARIA attributes are essential to providing a usable experience for impaired users.

For example using link-to:

    {{#link-to 'my-route' aria-label="This link will take you to some other route." title="Go to other route name"}}
        My Link Text
    {{/link-to}}

renders:

    <a id="ember1012" href="#/my-route" title="Go to other route name" class="ember-view">
        My Link Text
    </a>

Due to the number of WAI-ARIA attributes and their validity in various tags makes it difficult to suggest an exhaustive list. Perhaps any attributes with the aria- prefix added to a helper could just be rendered?