Google is at the moment a default search engine for many browsers, and this is something that developers are bound by contract. On the other hand, that same contract can be reconsidered at its end date, which is something that Safari is currently facing.
A contract binding Google and Apple binding will come to an end by the end of the year. This is a big opportunity for Apple to renegotiate the deal or even to find a replacement for the well known search engine.
There is little chance that Apple will turn to its competitor, Microsoft Bing. Google has also become a competitor with its devices under ChromeOS and Yahoo! would seem the most likely solution.
Nothing is still carved in stone, but if it should be, after retrieving the Mozilla USA contract, Yahoo! could still expand its visibility with millions of devices in the world running on OS X and iOS.
Source:
Expreview.com.