Logic is a central area 
I quoted above from Syracuse University's web site  the "four core areas of philosophy" that students must study are The History of Philosophy, Ethics and Moral Theory, Metaphysics and The Theory of Knowledge (Epistemology), and Logic. Now from Harvard University  basic required courses are an introductory course and one each from 1. Logic, 2. Contemporary metaphysics, epistemology, philosophy of science, philosophy of mind, philosophy of language, 3. Ethics, political philosophy, aesthetics, and 4. History of ancient, medieval, or modern pre-20th-century philosophy. Stanford University  basic required courses are an introductory course and one each from Logic, Philosophy of science, Moral and political philosophy, Metaphysics and epistemology, and History of philosophy. Major research universities seem to agree that all undergrad. phil. majors must take a logic course (and, incidentally, that metaphysics and epistemology can be lumped together at this level). While what undergrads. must take is hardly the be-all and end-all of phil., it certainly indicates to me that logic is a major area in the minds of academic philosophers. I also consider "The Development of Logic" by Kneale and Kneale  to support this position; from pg. 1 it puts "not simply valid argument but the reflection on principles of validity" in the context of Plato and Aristotle. (Of course they also discuss it in the context of math.) I contend that logic is a central area of phil. and merits conclusion alongside ethics and metaphysics/epistemology as the three major areas of phil.