On July 11, 2007 I did a post on progress of Australia-DARPA "HyCause" hypersonic ramjet research. Something that may now be using results from that research (or working in parallel) is the "HyFly" test series.
From Defence Talk.com, October 6, 2008 comes the following:
"The DCR engine is designed to accelerate HyFly and sustain flight at Mach 6," said Carl Avila, director of Advanced Weapons and Missile Systems for Boeing. "This will be a major step in the development of a weapon system that could revolutionize the military's ability to respond rapidly to time-critical threats hundreds of miles away. It will demonstrate that hypersonic weapons are viable and will put us one step closer to making a high-speed strike weapon available to the warfighter."
Just like subsonic cruise missile doctrine shifted from purely nuclear to mixed warhead uses hypersonic may be mixed - although the expectation might lean towards nuclear till experience proves otherwise.