If you mean "the future" of mobile phone operating systems, you may be right about the three horse race. But Windows Phone hasn't proven itself yet. For now I would say a two-horse race.
Microsoft has a terrible track-record in mobile. Just because the marketing hype talks about a three-horse race, doesn't make it so.

In tablets it is even less clear. iPad is the only really successful tablet device today. Will Google and/or Microsoft introduce an equally successful tablet? Far from certain. This definitely isn't a three horse race yet.

And in laptop/desktop computers? Apple is making big inroads in the high-end segments and among students and youth, but it is still over 90% Windows. Chrome OS or Android for netbooks look ok, but isn't big at all. Other linux distributions like Ubuntu are making impressive progress, but still have a relatively small user base. A three horse race?? Really?

Also "the future is closed", really? Today everybody uses some sort of open-source software product in one way or the other. That wasn't the case ten years ago. The fact that people don't use an open OS, doesn't mean they don't use open-source software on it. At least not today, so why in the future?