Provide ability to run tests from the browser

I've just read something about the Play framework, which sports a
pretty interesting test runner, see screenshots under
http://www.playframework.org/documentation/1.1-trunk/scguide2

I was wondering, would it be possible to have Grails provide a similar
facility ? Running unit and integration tests directly and
continuously from the browser would have several huge advantages:

• The Grails app could still run simultaneously.
• Tests would run much faster as there is no need for restarting the
  Grails environment each time.
• You would get instant feedback without leaving the browser window.