It's really tough to find the appropriate time to cut spending/raise taxes after implementing a stimulus plan. Do it too soon and we the economy takes another nose dive. If we wait too long the mounting debt could harm the dollar and the U.S.'s credit, which would in turn destabilize the world's economy again.
The U.S. has never defaulted on a loan, which is why the U.S. treasury bonds are the standard of comparison for basically everything (and to think before Bush took office economists were concerned that the national debt was going to shrink to zero, which could have destabilized the world economy because there would be no treasury bonds). As high as it is we aren't in crisis mode yet with the debt. Other nations aren't stupid enough to recal U.S. debt. It needs to be addressed sooner rather than later, but realistically in my opinion we should probably wait until consumer sentiment rebounds a bit or we risk undoing any progress the economy has made.