It's still not nobody. And having Firefox playing a significant role will prevent situation which existed in the past where many sites were "IE only". We don't need "WebKit only" sites.
There is a difference between "WebKit only", which means you have to support some N number of standards (CSS 1/2/3 for example) and "IE only" sites, where you have to run Windows and support ActiveX.
There are enough WebKit browsers specific things which are not standard to make "WebKit only" situation a problem. In general, well balanced browsers representation makes web developers think better and be more responsible.
