Overly pessimistic on US dollar?

Just looking at the present data in term of federal debt to GDP for the US is not as bad it's seems. However, looking into future, from Bill Gross's tone, is very worrisome:

Private sector deleveraging, reregulation and reduced consumption all argue for a real growth rate in the U.S. that requires a government checkbook for years to come just to keep its head above the 1% required to stabilize unemployment. Five more years of those 10% of GDP deficits will quickly raise America’s debt to GDP level to over 100%, a level that the rating services – and more importantly the markets – recognize as a point of no return. At 100% debt to GDP, the interest on the debt might amount to 5% or 6% of annual output alone,.......

...... promise that Federal spending for Social Security, Medicare, and Medicaid will collectively increase by 6% of GDP over the next 20 years, leading to even larger deficits unless taxes are increased proportionately. Collectively these three programs represent an approximate $40 trillion liability that will have to be paid. If not, you can add that present value figure to the current $10 trillion deficit and reach a 300% of GDP figure – a number that resembles Latin American economies such as Argentina and Brazil over the past century.

The obvious solution to both dollar weakness and higher yields is to move quickly towards a more balanced budget once a sustained recovery is assured, but don’t count on the former or the latter. It is probable that trillion-dollar deficits are here to stay because any recovery is likely to reflect “new normal” GDP growth rates of 1%-2% not 3%+ as we used to have. Staying rich in this future world will require strategies that reflect this altered vision of global economic growth and delevered financial markets. Bond investors should therefore confine maturities to the front end of yield curves where continuing low yields and downside price protection is more probable. Holders of dollars should diversify their own baskets before central banks and sovereign wealth funds ultimately do the same. All investors should expect considerably lower rates of return than what they grew accustomed to only a few years ago. Staying rich in the “new normal” may not require investors to resemble Balzac as much as Will Rogers, who opined in the early 30s that he wasn’t as much concerned about the return on his money as the return of his money.

http://www.pimco.com/LeftNav/Featured+Market+Commentary/IO/2009/IO+June+2009+Staying+Rich+in+the+New+Normal+Gross.htm

Will the US debt goes over 300% GDP? Do I have worry? Yes I do but let's hope the decline will be gradual and orderly. However, living in Asia makes me feel better hoping our currency will rise against them.