The wonderfully sort-of-secret X-37B is back on terra firma after a long stay in space. Very little information beyond its appearance, dimensions and the fact that the Air Force is deploying it is known about the vehicle, which looks a lot like a mini space shuttle. The vehicle can stay in orbit for at least nine months.
As someone who spent five years at Space News -- much of that time covering intelligence issues -- I'm going to engage in some informed speculation.
It could take advanced sensors into space for testing and, probably, allow sensors to operate from the X-35B as a large, stable platform with an independent power source. That power source (folding solar panels) might free sensors from carrying batteries, which would make them much smaller and lighter and perhaps extend their operational life.
One set of sensors the nation desperately needs would be related to space situational awareness -- small telescopes, infrared and other sensors. The X-37B might be ideally suited to this sort of mission.
The dimensions would appear to allow the vehicle enough cargo space to loft small satellites into orbit. The Air Force has been striving to come up with ways to deploy small satellites into orbit rapidly. Putting an X-37B into space with one or more satellites would let the military effectively preposition a bird for use in a crisis. The concept of operations developed by the Pentagon for Operationally Responsive Space focused on rapid deployment of smaller satellites, as well as the ability to change how a satellite already in orbit might be used. But the focus of ORS is on adapting software and manipulating data to achieve those results, not on heading into space to physically fiddle around with an orbiting satellite. The X-37B might be used to manipulate a satellite, though such operations are quite challenging and would only be done in extremis.
The X-37B can apparently be maneuvered while in space so low earth orbit deployment of small satellites over a theater might be possible, meeting another of the criteria of the ORS CONOPS. Combatant commanders have pressed hard to get the ability to deploy communications and electro-optical satellites over a theater with relatively short notice. With space assets, that probably doesn't mean much less than three months. If my surmises are correct then putting an X-37B up at the first indicators of a crisis could give the US a flexibility it does not currently possess.
On the issue of whether the X-37B could deploy space weapons or be used to interfere with enemy satellites, I think it's really moot. We already possess the ability to shoot down satellites, as we proved with our own destruction of US 193. And we possess the ability to dazzle enemy satellites, as the Chinese did to us several years ago. And, if you talk with space experts, they say that in event of war we would be much more likely to attack ground stations to cripple satellites. If you destroy or use cyber assets to cripple a ground station the satellite is just a big chunk of metal zooming around the earth.