How to implement a wow (world of warcraft) dungeon entry shader?

I need a shader (or maybe a post effect) which used to do the job like wow dungeon entry (a little like the swirl effect, with “smoke - like” effect), need somebody to give a clue, thanks.

You could use the blur camera effect then rotate the camera around its local (i think) Z axis.

http://docs.unity3d.com/Documentation/Components/script-Blur.html