We just released a toolkit for integrating ember with karma, requirejs, and qunit.
It has examples of how to unit test models, dom test views, and dom test components. It is setup to watch files when they change and re-run the tests automatically.
https://github.com/practicefusion/karma-requirejs-qunit-ember-tdd
Hopefully this helps people out who want to build their ember apps using test driven development (tdd). Feel free to add any issues and to fork and submit pull requests!