I am trying to displace a plane with a movie texture. The bumpmap does not recognize a movie, and does not displace the plane.
You would need to do this manually trough scripting. (I'd actually need to check if Unity currently supports GetPixel()ing on a movietexture). assuming it does for a second, you could read color values for your pixels, and use those to change coordinates of vertices in your plane mesh.
Depending on what you're trying to achieve there might be a more effecient way than using a movie texture. Hard to tell though, as your question is rather slim on details :)