With Windows Phone and Windows RT, he claims that Microsoft is planning to merge both operating systems together. He doesn’t give any more information regarding the matter, but it has been rumored several times in the past that this is Microsoft ultimate goal for both Windows Phone and Windows RT.
Of course this would be the logical move, and should have been Microsoft’s ultimate goal all along, this would allow both the tablet space, and the phone space to piggyback off each others success, rather than having each of them try and make it on their own. With the most recent rumors giving all the gritty details about Nokia’s upcoming RT tablet it starts looking like smart idea, push out a tablet now, and have it merge with WP later where you’re already leading.
Then again these are still rumors with no concrete evidence, so you never know; the source also makes mention of what to expect in Windows 9 and 10 (not WP) so check that out below.