Airplay is just a wireless standard made by Apple. There is nothing special about it (except maybe that it is widespread). You still need to have something connected to the projector that is running Airplay and acting as a receiver. In that case you can do the same thing with Android or Surface. All you need is a small PC running ....
Of course none of this is as easy as Apple, which is excellent at implementing such things and has the closed vertical structure to do it, but it can be done. Besides how cool would it be to bring your Xbox or PS3 into a meeting