The principles behind RWD might accompany us for quite a while. What is "the future" on the web? A few years ago, people said that this time around HTML and CSS would be a thing of the past, CMSes would be replaced by Facebook and similar sites, nobody would use websites anymore for personal use and that commerce would be done through social media channels. We know how these predictions turned out...
This industry is moving fast, yes, but technologies don't. Instead, the technologies and methods of yesterday get improved on and extended. But, in essence, we're still using the same tools we used 10 years ago. They've just progressed to become richer, more complicated, a lot better and a lot worse.
The same goes for RWD. It's a snapshot of where we are and the ideas behind it will continue to be relevant, though probably not in the same way we define it here and now.
But to answer your question, RWD, or rather, the principles of RWD are indeed a standard today. They've been for quite a while but a catchy buzzword was needed to have a larger base accept its validity.