If you consider yourself to be mature enough, to drop testing pay attention to the minefields you may be leaving behind.
Recently a friend discovered this blog. She asked me why do I write so much about Expressive Design. I will try to give some overview of the topic and link to the many articles in this blog about specific points.
Using mocks and interactions as drivers for test cases you away from good specifications; always keep in mind that we should only bother about what, not how