Retina-caliber products feature double the pixel density, thereby causing web graphics to often appear blurry and pixelated. This is because the technology that had been used to build websites is no longer appropriate for high-definition displays. While you won't need to go so far as to build a new website to accommodate Retina technology, you will need your site developer to make a few reasonable adjustments:
Graphically typeset text should be swapped out for web text. Services like TypeKit offer an ever-growing pool of fonts.
Replace traditional bitmap graphics with browser-generated effects. CSS3 offers a wealth of new tools to recreate traditional design elements within the browser, all of which scale perfectly.
Use Scalable Vector Graphics (SVG) where possible. These files scale up infinitely in size. At a minimum, use an SVG file for your company's logo so it appears crisp on all displays.
By implementing these techniques you not only ensure your site displays optimally on high-definition displays, you may also enhance loading times, much to the appreciation of your site visitors.