Yes, its true yahoo has tied a knot with Bing, it’s not that they have got married each other but if you will go with exclusion Korea whether on cell phone or the desktop yahoo will be fully powered by the unlike search engine and that is the Microsoft’s Bing.
Now Yahoo search is not giving their own algorithmic search results any longer, like they haven’t being doing as a consequence in the U.S. in Canada ever since August 2010. Country after country, Yahoo has been handing over their search technology and search engine to Bing (the Microsoft search engine).
The next day, yahoo announced that the procedure has totally now been completed, with the exemption of the Korea. But the question is why not Korea? Because of "a three-way amalgamation among Yahoo, Microsoft and Daum, residues, and is probable to complete by the end of the year."
That being said, this was the plan and it has been executed. Still the Paid search is not completely transitioned over. It is in the U.S., Canada and many other countries, but not at all places, not yet.