The USAF and Boeing will launch the X-37B—the first military orbital space plane if you discount the secret military shuttle—on top of an Atlas V rocket in November. They want to test its flying features in space and during atmospheric reentry. And probably its anti-matter rays and nuclear bays and hyperspace engines too (but of course, they are never going to tell you that). However, there seems to be a conflict with the civilian space program which may push one of the Moon exploration missions to 2009.
According to Aviation Week, the X-37B test will use a launch slot previously reserved for another Atlas V, which would have carried NASA's Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite. This mission would have to be posponed to February-March 2009.
At first sight, it looks like the US military is starting to feel the heat of the May 2010 deadline for the space shuttle program—which will limit their capacity to service military satellites as well as their secret orbital base, with all those nuclear heads and chemical lasers capable of blowing up Tehran in a millisecond. However, the reality is that an "end-of-2008" launch was announced back in 2006. The spacecraft—as well as the X-40, its predecessor—has already been tested numerous times, one of them flying underneath the White Knight from Mojave Spaceport. [Aviation Week]