An interesting post from Google's QA about patterns to testing

http://googletesting.blogspot.com/2010/01/interviewing-insights-and-test.html

I think this is good point and reflection but IMO professional QA guys combine all the best from this classification and care this suite in daily activities. I don't like one-sided approach as it risky to limit own vision. Also flexibility should be a part of career path since different projects expect different approach as well as thinking.