Excellent piece in today's New York Times (here) on the Supreme Court's lurch to the right (measured not against the very liberal Warren Court but the pretty-darn conservative Rehnquist Court). That move is almost entirely the result of a single replacement: Samuel Alito for Sandra Day O'Connor. O'Connor was the pivotal vote on the Court. Now, Anthony Kennedy is in that role, and he is marginally more conservative, particularly on issues involving women, children, and the elderly, than O'Connor. Meanwhile, Roberts, Alito, Thomas and Scalia have succeeded in pulling Kennedy farther to the right.
What about the Sotomayor and Kagan appointments? They are almost inconsequential in terms of the Court's overall direction, because they replaced retiring justices who were of a similar ideological bent.
Whether or not the Court's move to the right is a good thing is, of course, in the eye of the beholder.