Yes, Zen Buddhism will be the "religion of the future" due to its rapid spreading and adoption rate. As more and more people convert to Zen Buddhism, its status as one of the largest religions in the world will only increase. It is only a matter of time before it is adopted in the Western World.
I think that Zen Buddhism will be the religion of the future because they are believing in Zen now so all they will do is tie in the Buddhism and people will begin to convert over. I think that people that believe in Buddhism believe in Zen so tying the two together will not be as hard as it seems and will have a lot of follower when it is tied together.