Interestingly, I received a call today from AA RTW desk advising that my fare was re-calculated from 3 continents to 4! Seems that rules have changed recently as they now allow you to backtrack via Asia at n/c, regardless of whether you actually take advantage of this option. Makes you wonder if someone from AA is reading these posts???

Looking more like YYZ will now be the starting point. Here are the quotes that I just received from AA for originating in Canada (all in USD):

Economy - 3 zones $2180.35
4 zones $2559.25
Business- 3 zones $3886.63
4 zones $4570.63