To add to Mark Ambinder's list of the seven reasons why Hillary Clinton might consider remaining in the race -- I'd like to propose an eighth. Perhaps she can actually make money the rest of the way out? By having a schedule heavy on fundraising, cutting back advertising to a bare minimum, and letting her staff dwindle by attrition -- there surely are plenty of exhausted folks on Team Clinton -- it's conceivable that Clinton could use the pretense of a campaign in the remaining primaries in order to help to pay off any campaign debt that her team has accumulated.
To some extent, the Clinton campaign may already have hedged its bets in the remaining states. They have 17 field offices open in the six remaining primary states: seven in Oregon, five in Kentucky, four in West Virginia, one in Montana, and none in South Dakota or Puerto Rico. Obama, by contrast, has 44 field offices open: 17 in Oregon, 10 in West Virginia, seven in each of Kentucky and Montana, three in South Dakota, and none in Puerto Rico.