Don Peterson has a long disquisition at SpaceRef about why we shouldn’t go to Mars via the moon.

The problem with this, of course, is that it presumes that the only goal is to go to Mars. He seems to recognize no intrinsic value in returning to the moon, or in establishing a base there. He’s welcome to his opinion, of course, but that’s not in concert with the president’s goals, and in my opinion, he’s wrong. There are many reasons to go back to the moon, as were laid out by several witnesses to the Aldridge commission a few weeks ago, regardless of its eventual utility in supporting a Mars flight.