I have an AMI that I created from Windows server AMI, that's used in the EC2 for Poets tutorial. It worked really well at first. I had to launch a new instance a week or so ago, and waited for over an hour and it was still telling me it couldn't get a Windows password for it.
I will, once I get one of these guys to launch, create a fresh AMI and hope that clears the problem. Whatever happened this is really bad. I assumed that the stuff inside the AMI didn't need to be backed up. Bad assumption!
Update: At 9PM still no Windows password. Posted question on Amazon support.