Designing across all digital platforms is standard.
It’s almost incomprehensible nowadays to build a website that isn’t responsive, meaning accessible on multiple devices (phone, tablet, desktop etc.). The technique has developed to the point that most designers no longer say, ‘responsive web design,’ we say, ‘web design,’ and mean exactly the same thing.
As the tech industry continues to develop new devices, with new capabilities and limitations, the challenges we face as web designers will inevitably change.
The future of responsive web design, or perhaps simply web design, is one in which designs are not just screen agnostic, but screen independent. If your sites are optimized for screen readers, then they will function effectively on the next generation of web browser.
See some examples of Darren Wotherspoon's Web Design samples