Its about time. I worked on the MX missile (Peacekeeper) at Martin Marietta back in the early 80s. It carried 10 warheads and was far more accurate than the Minuteman III, but sadly they were negotiated away in the START treaty, and were dismantled.
On the other hand, I should add that the threat of those 10-headed beasts, along with SDI, was one of the key factors that drove the Soviet Union into the ground.