Although the speakers are talking about a python application, rather than a Java one, this recorded presentation by two engineers at Google that maintain Google Code touts the motto of the Arquillian project:

"Stop mocking, start testing"

The engineers came to this conclusion the hard way, by cutting their teeth on integration failures that occured when transitioning the application from the mock world to the real one. They don't discount the value of mocks entirely. For instance, their tests cannot invoke the real user account or billing system (and perhaps yours cannot either). They conclude that mocks are valuable, sometimes even necessary, at the interface to an external system. However, if you rely on mocks to avoid code integration, you end up with lots of mocks to maintain and little faith that your code actually works (i.e., a nightmare).

What is your take on this video? (Does it make you want to avoid python?)