Restoring from backup has hung

I just had Apple replace my HDD in my iMac. I'm now using Migration Assistant to restore my backup from a time capsule. This process has taken quite a few hours. Anyway, I'm in the home stretch. It's about 92% done, and it's saying that I have 55 minutes remaining. The problem is that it has said that for over 5 hours now.

I'm afraid the application is hung, the machine isn't locked up - I can still move the mouse and it will bleep if I press the spacebar several times, but what do I do now?

Can I force quit? Reboot? Disconnect the AirPort Time Capsule? Won't all those result in very bad things? What are my options here?