They are claiming the following:Please, hop on over to the spec page right now: http://www.apple.com/macbook-pro/specs/ , scroll down to the battery life claims, what are they claiming? Don't trust me. You do it and see for yourself. What are they claiming in writing right there on their own website?
Battery life varies by use and configuration.
As you said: go take a look at the website and see for yourself. Do read the foot notes as well because the last one specifically tells you how they measured it plus warns you that battery life varies by use and configuration. Anyone who spends a few seconds thinking about how a computer works would have thought of all this by himself without having Apple to explain it to them.