No, there is a plan, and it has been done before. President Carter faced the same dilemma in 1978. His solution was to simply print enough money to pay all the interest and continue to fund the deficits. Then, inflation cut the actual value of the bonds in half. Obama will do the same thing (is doing the same thing), for the simple reason that he has no other choice.
Of course, that will make the interest rates on new bonds soar, but that problem is for 3 years from now, which will make the total debt soar. Social Security benefits will drop, as the stated (admitted) inflation rate is always well below the real inflation rate.
There will probably also be raises to the retirement age, and SS tax hikes also.