I think PS is useful in medical school. For instance, you use physics in cardiology to understand the resistance of blood vessels, cardiac output, compliance, etc. It's also present in respiratory with Laplace's law and some other equations. Gen chem is used as well, but by the time you get to medical school, the basics have become so ingrained you take it for granted. Topics like le chatelier and how acids/bases work are second nature, but they're rooted in gen chem.
VR is used as well through its emphasis on critical thinking. I don't think I need to explain why critical thinking is necessary.
WS is helpful in that it demonstrates how well you can synthesize new ideas, see different sides of an argument, and, most importantly, it shows how well you can communicate your ideas to others.
BS I believe is pretty self explanatory.
On the whole, the MCAT is about taking the basic knowledge you obtained in undergrad and applying it to new situations. You do the same thing in medical school except the knowledge base is far, far greater.