Ember 7.x-2.0 alpha is now available!
The 7.x-2.0 version has been re-built from the ground up using sass and compass. Ember is designed specifically with Spark users in mind, though it can be used as a standalone admin theme as well.
Ember theme was also built to work with Navbar module (Toolbar in Drupal 8) and includes module stle overrides for Views, Ctools, Panels, Media, Workbench and Features.
The Ember style guide can now be found on the Ember documentation page. Not all of the style guide has yet been implemented in the theme. Your help is welcome!
Support for Contributed Modules
There are a wide variety of contributed modules that persist into the front-end where Ember cannot control styles. Edge cases also exist where Ember styles cannot cover specific modules' needs. It would clutter the theme's codebase to provide coverage for those specific use cases. The Ember Support module exists to address these issues.