Windows Holographic is out there with end-users. Albeit with some/many shortcomings and obviously still being developed (like every other OS) -- I would compare it more to iOS 1.0, which was pretty stable but also had many short comings.

Apple and Google haves not released anything for end-users or even demoed anything... so I still feel Microsoft is ahead. Obviously, I don't know what Apple and Google are working on internally (or Microsoft for that matter).