so it looks like there aren't going to be any lore retcons. basically when they announced it people kind of flipped out (understandably) and the reason they went with is that they didn't want new sounds. the voices and sound effects are all pretty iconic and people said that it would take away too much from wc3 to make changes like that. so blizz agreed and they are keeping all the original sound files, which means they can't make any story changes that weren't recorded already. so the changes they are making are basically geographical. they want to update some of the maps to better fall in line with wow, which makes sense and i'm fine with that.