Possibly hobbled by my lack of imagination again...
The article here waxes very enthusiastic (naturally) about putting stuff on the moon, especially in the light of the discovery of water...but I come back to the same concern, namely "we're going back to the moon to do what, exactly?"
Spudis, who I admire, seems to boil it down to becoming a space faring species. Is that the impetus, though, that's going to get us there? People didn't move westward in America because they wanted to become Californian. That was just a side-effect of more practical motivations.