If you want to talk about the oil, then letting Quadafi squash the revolt would have been much quicker and cheaper for us. But I understand that's not the real issue for you, you're just adding that into the mix.
The humanitarian issue is a solid one to be concerned with. Where were you on the Saddam Hussein issue? Anti Bush?
As far as this being a good thing done by Obama, what he's done is open a power void in a part of the world that's rife with what many think will eventually lead us to the third world war. Lets not get too carried away with "he did something right" just yet.
However, I will say this. I think that there's a good chance that our leaders (including those from France and England) know more than we do about who has the better grasp on that power that's now left in the air. I don't think we get involved otherwise. At least I hope this is the case. But it wasn't Obama, remember that he had to be convinced on this by the European leaders.
At any rate, I just don't see cause for giving Obama much credit beyond saying he did what any of us would do. And I don't think that those on the other side of the aisle would have done anything different, regardless of the political comments they may make after the fact.