It should do - I'm part way doing the same thing myself - as long as your movies are in the 'iTunes' folder, everything will transfer over. It all works fine, but it can be a pain in the backside sometimes having to have the external drive plugged in when you want to run iTunes. I'm also much more nervous about losing my music collection now that it's steadily being removed from the internal HDD.
It should do - I'm part way doing the same thing myself - as long as your movies are in the 'iTunes' folder, everything will transfer over. It all works fine, but it can be a pain in the backside sometimes having to have the external drive plugged in when you want to run iTunes. I'm also much more nervous about losing my music collection now that it's steadily being removed from the internal HDD.