Responsive web design makes it easier for people to view your website on any size screen, large or small. Green Sprout Forum is built on a responsive platform, so we don’t need a separate mobile site.
User experience in an important part of the success of you website. Google looks at user experience for SEO. If visitors are enjoying their visit and finding the quality information they need, they will stay. Even better, they will buy from you.
Responsive web design is here to stay and will become the industry standard. Here is a good post about responsive design from SEOmoz.