People seem to think it's an issue with the solar panels on twitter. It's looking like the solar panels didn't deploy.

As noted elsewhere the issue is with the software inhibiting the activation of the thrusters. They delayed solar panel deployment because the capsule doesn't have attitude control yet.

Oh wow, that's even worse news. Hopefully the override works.

It's better, I'd say. The chances that it's just a software or sensor problem are pretty high, and they can just issue an override.

I would think that without thrusters that it would be unable to dock with the ISS.

According to http://www.spaceflightnow.com/falcon9/005/status.html

    SpaceX says one thruster pod is working, and two are "preferred" to deploy solar arrays. Four thruster pods are on the Dragon spacecraft.

    "We are working to bring up the other two in order to plan the next series of burns to get to station," a SpaceX spokesperson says.

And at 11:40 EST:

    "Thruster pod 3 tank pressure trending positive. Preparing to deploy solar arrays," Musk just tweeted.

    At least two thruster pods are needed to deploy the power-generating solar arrays, which stretch 54 feet tip-to-tip.

So it's looking positive that they'll recover from this.