Jacob Levy argues that abolishing earmarks would indeed save money. It won't cut the deficit by much, but his logic is sound:
Republican earmark supporters have been saying that abolishing earmarks transfers allocation authority to the dreaded Obama Administration. Well, yes. And if you tell a bunch of Republican legislators to decide how much money to give to the Obama administration to allocate, they'll come up with a smaller number than if you tell them to come up with an amount for them to divide up among themselves to allocate. Indeed the same holds true for members of the President's own party.