From what I can tell, ViewSwitcher is used if you want to switch between two views like you said. Useful if you have 2 views that you have to go back and forth fairly regularly. And the class implements a ViewFactory if you wish to use it.
However, ViewFlipper can be used if you want to periodically change the views. Say like an automated flipping book of some sort. Though a custom-adapter gallery is much better at this.
And yep, that’s all. They really aren’t that much more useful than the ViewAnimator. Why Android development makes anything is really a mystery to me.
I would normally just prefer using a ViewAnimator because it gives you more freedom and thus flexibility in how you design. But if you want features like the ViewFactory and you only got 2 views use the ViewSwitcher. If you want to be able to periodically change views use ViewFlipper. If you don’t need either use a ViewAnimator.