In IW and IT the plants moved like there was a breeze. I believe there is a topic somewhere on the Mesh's board where there are moving plants that are available for download. Ill go search for it in a bit.
Im not sure about wind blowing your mane though. It would be difficult giving the mesh an animation that would fit with the wind, it would take hours to modify every mane mesh.
I think a large amount of coding would have to be done to get the wind to blow at different times and directions, you cant have wind blowing non stop in the same direction.
As cool as that would be i dont think that would easily be done.