There is a pretty good story behind this. That is, how we found and managed the OAuth protocol security threat identified last week. In many ways, the story is much more important and interesting than the actual technical details of the exploit.
For everyone involved, this was a first-of-a-kind experience: managing a specification security hole (as opposed to a software bug) in an open specification, with an open community, and no clear governance model. Where do you even begin?
But right now, I know you want the technical details.