I don't think it was any one thing or moment for me, but you are correct. WoW now occupies 2 special places in my heart. The first, and happier, place is one filled with great memories and friends I made over 3 years.
The second place is well.... filled with hatred and utter astonishment. No matter how hard I try to describe my hate for WoW, I can't come up with anything specific or focused. It is just an overall feeling of being cheated and secretly betrayed by Blizzard and their amazing ability to keep me and so many other people playing for so long.
I cannot tell you guys how fucking happy I am to have another game to play. I'd rather check this guild's forums 8-10 times a day than spend more than the time it takes to get 10 2v2 games each week with a real life friend whom I haven't seen in person in over a year.