All this discussion of whether to raise the federal debt ceiling is shenanigans. Congress approves a budget and projects a deficit. The deficit needs to be financed and thus automatically be included to raise the limit from whatever it was.
Current ceiling is $14.294 trillion - 2011 fiscal year projected deficit is $1.3 trillion. Thus at the budget time, the limit should be $15.594 trillion. This will act just like credit card limits. It does not mean that we borrow to the hilt. Congress can cut spending or increase revenue to keep the actual debt reasonable.