What can we say but "congratulations!", I guess?
Its so out of the norm that few of us would be able to comment
usefully, and my own speculation on the matter hasn't gotten us anywhere.
Let us know if this indeed leads to an offer or already is, or whatever.
I will definitely let you all know what happens. I'm still not really sure what's going on, or if there are multiple candidates, or what, but I am being brought to campus already. So they do seem to be serious, and moving very quickly. Hopefully the visit will make everything clear...
I'm also expecting a decision from my two other campus visits in the next week or two, so between the three, I'm feeling pretty optimistic that my job search might finally be over soon.