I'm sure everyone is curious what happened to cause the site to go down.
The very short version is that a key file that holds all the site settings (server, database server, key pwd's, etc) looks to have become corrupted. That resulted in the errors you saw in the browser.
I requested a restore of the site from our nightly backup and moved a good copy of the corrupt file back over this morning. Everything looks great. We have no loss of data as only the 1 file was replaced (and that file never changes).
On the plus side, we've proven that our backups are good and that we can recovery from them quite easily. Just takes a little time for the restore process to complete.
Thanks for your patience everyone!
~D