I dont think so that facebook will create his own cryptocurrency. For what? Yes it would be much easier for people to transfer money, but i think the people of facebook and many other big companys are not convinced by cryptocurencies. So they would either have a partnership with visa or paypal or any other companys who make digital payments instead of a own cryptocurrency.
Why do you think so? I really think that its cool idea, we need just to wait till finish the whitepapper, and than have a discuss.