Thus endeth the process - had my N-400 interview in Seattle yesterday. I was called in about 40 minutes past the scheduled time, finished up in about 15 minutes. Heading out I just missed one oath ceremony and had to wait about an hour for the next which was the last of the day.
I had already scheduled an urgent travel appointment at the Passport Agency for today on the assumption that I'd pass, had to wait well over two hours past that appointed time, but I should have my passport in a day or two, I can't be in travel limbo for 2+ months.
Surreal how quick this last step was compared to all the other steps...