I've gone through the 2011 thread a couple of times as well. What I find more useful though, are the compiled stats of everyone on gmatclub who applied that year (first page, first post of the thread), when they received an interview, when it went complete, when they received a decision etc.
It's pretty cool because you can also see what the average waiting period is to receive an interview invite and get a decision after the interview is complete.
MDF, just for reference, there were a number of people last year who had to wait longer than a week for their status to change to "interview complete." I think it basically depends on when your interviewer submits his report. I wouldn't sweat it just yet if I were you. However, if it still doesn't change in another week, I would call the school. They will contact the interviewer and remind him to finish the report.
Good luck!