Idk what Gwen would be doing in Cantha, especially for her wedding, I'm assuming it'll probably be the Emperor. Plus, the name gives the location away, if we didn't already have the information: Winds of Change, Jade Wind, Cantha, Factions.
As for the hero, it's something we won't expect. I think the biggest curve ball they could throw at us is something like Undead Rurik, but that would be a horrible spoiler if you decided to play with someone who is still in Ascalon. Aside from that, I'm thinking only of Cantha, maybe a Shirokin turned good. Or maybe it's Vizu! That would be awesome! I've heard rumors about it being a sin. I can see Vizu coming out of her rest to kill with us, again. Or maybe we could even choose which T-Temple ghost we wanted to have as a hero, that seems horribly complicated, and unlikely, but that's where my money is. Since it has to do with the Winds of Change, Wind=Shiro, we will need someone who was there when the Jade Wind happened, or caused it to happen, IE. Vizu, in order to change it.
PS. I'm also putting money down that the reward weapons will go into the HoM like the Oppressor weapons. Just saying.