This happened to me, I was going for the Customer Solutions Engineer role.
After the phone interview, they flew me to Mountain View. All day of one to one interviews; some face to face, some over Google Hangouts, did a coding-problem using Google Docs.
Got a phone call from the recruiter a week later saying I had passed all the interview however they had to go with a person who had a bit more experience in the particular customer industry they wanted to place the role. Judging by the questions and angle they were asking, I think it was Television (I come from the movie industry).
They still phone me from time to time again, asking if I'm interested in other roles (had an interview in London last year with their Android Team), so I guess time will tell if they find a position for me.
This pretty much matches exactly what I experienced at Google. I was fortunately enough to get two interviews for two different positions in two different locations.
The only thing I could add is that, occasionally there is a distinct lack of communication between the interviewers during the day and you do find yourself getting the same questions asked of you.
The classic Google-esc questions are still asked but they aren't as tough as people make out - just speak loudly, don't close up and vocalise your thought-process. It's about the working not the final answer.
Definitely will be looking at the official Obsidian sync plan now.