This is always a possibility. After all if they can buy in Siri or build their own mapping service, why not search? The question is why do that, especially if doing so will cost you not just the price of the service but also £3bn in recurring revenue?

To be compelling, doing so would either have to earn them the cost of the service plus £3bn a year, or it would have to mitigate a strategic risk. With maps, Google had turn by turn directions on Android but wouldn't add it on iOS. The only way for Apple to get that feature was to do it themselves. But there are no such risks with Search and there is always Bing.

Apple does already provide a limited search engine, of course. It's the thing that returns "Suggested Website" when you type in the omnibar, and very often it finds what you're looking for without the need to go to Google (or DDG, or Bing). For one random query I just tried, it came up with a better result than DDG's #1 or #2, which is sad but not too surprising.

They won't do that. The current arrangement with Google is quite good for both parties. It's not smart to start another battle with Google unless there is some to gain. 3 billion in profits is quite good. It's hard to imagine how Apple can make that much profit from their own search engine.

7 more years until Facebook thinks they will be ready to compete.

http://www.businessinsider.com/facebook-will-challenge-googl...

DuckDuckGo is just Bing with a filter. It's not a search engine in and of itself, so there's nothing much there for Apple to buy.

Apple could use anonymized browsing and searching data from Safari to launch it's own search engine if Google pulls its current deal.