Yes i agree that wind is a good idea, but while on the subject of varying character movement, why not include different animations for different weather effects (rain, storms, flying on an animal etc), depending on character status (diseases, poison etc.) and also auras on weapons if they are magical (like in Dungeon Siege).
How about different idle animations like when you leave your character for, say, 3 mins, each race does something different. Just an idea;)
Most certainly something to be experimented with, because animations such as ones described sound really cool.