Who is going to lend us money after June 30?

Bill Gross is taking a wait and see attitude:

Investors should view June 30th, 2011 not as political historians view November 11th, 1918 (Armistice Day – a day of reconciliation and healing) but more like June 6th, 1944 (D-Day – a day fraught with hope for victory, but fueled with immediate uncertainty and fear as to what would happen in the short term). Bond yields and stock prices are resting on an artificial foundation of QE II credit that may or may not lead to a successful private market handoff and stability in currency and financial markets. 

The fear is that demand for US debt will fall when the Fed stops buying debt, and interest rates will go way up.  (Remember that the "price" of debt is the inverse of the interest rate, so when the demand for debt declines, price of debt falls, and interest rates increase.)

UPDATE:  Just saw this cartoon in the Economist.