Honestly if you want to do smooth animation like that you are going to have to use flash. That sort of animation is more suited to flash because of the fact that it is what flash is for. Photoshop is better as a design tool, to make cool designs to use in your flash creations. Also, if you can learn flash, it is 1000 times easier to create something like that.
You would have to go through a few hundred frames of animation to make it look so smooth, although I am sure you can find tutorials on how to do that. I will get one and post it up.