I for one would not be upset at all if/when Facebook fails. Another thing to consider: is your data plan advantageous? I tried VOIP on android over wifi once, it was terrible... almost unusable. With ideas like this, I am amazed FB is still in business.
They're certainly proving they are NOT too big to fail. Grasping at straws lately.
Pohl's law: Nothing is so good that somebody, somewhere, will not hate it.