So I went trolling around the left side of the Internet and came across this from the liberal Center on Budget and Policy Priorities. The title of the document tells you all you really need to know about it.

ADMINISTRATION'S LATEST 2004 DEFICIT PROJECTION APPEARS OVERSTATED;

Will Final Deficit Figure Be Presented As Progress In Deficit Reduction?

So, if the administration guesses high, they're just positioning themselves to look good when the number turns out to be lower...

And if the administration guesses low, they're trying to hide the true extent of deficit from the American people...

Heads they win, tails you lose.