You're so mean! I take it from "that" and "that" and "that", we don't have to worry this is the last book?
In keeping with the previous books in the series, some situations have a conclusion, others don't. It certainly didn't strike me as a series ending book. In any case, I'd like to think that the author would say if it was.
For now, I'm firmly of the belief that St. Mary's will be back to cause more chaos in the future. Er, past. Er ... you know what I mean.