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.
If you're not part of the solution, you're part of the precipitate.