At a conference in Seattle, Marcus Ash, a Group Program Manager for Cortana on Windows Phone, said that Microsoft was considering bringing Cortana to iOS and Android. The statement has been running rampant in the Windows Phone community as many see this as Microsoft taking its crown jewel on Windows Phone and giving it to other platforms.
To clear up the confusion, Ash took to Twitter to provide further commentary on his statements. He said that the top priority at the moment is to make Cortana the best possible personal digital assistant for Windows Phone customers and to push it out to more countries. He said that Cortana will be coming to the UK and China, in the coming weeks, not months.
He stated that the "showcase experience" will always be on Windows Phone, which makes sense because even if Cortana showed up on iOS and Android, Microsoft does not have the low-level access they need to deeply integrate on those platforms. Further, it will only be after they nail down the execution on Windows Phone will they consider bringing the digital assistant to Windows.
The Tweets seem to make it quite clear that the idea of bringing Cortana to other platforms, besides Microsoft products, is just that, an idea. Which makes sense, Microsoft is always asking the "what if we did this" question and the idea of Cortana on iOS/Android is an interesting proposition.
For now, though, Cortana will be staying on Windows Phone and will likely make its way to Windows in the future.
Source: Marcus Ash