Why would you need this for? SpotLight is a MUCH more inclusive technology that provides faster searches, doesn't require you to launch a browser and more comprehensive results. SpotLight can search all your media files for tags, ie songs by artist, movies produced by, pictures taken with, etc because it relies not on file names and mere content but metadata. Add to that the fact that it is extensible to search non standard file types that are defined by app authors, ie. XML files, propreitary file types, binary files, etc.
The only thing that this has that spotlight does not is the ability to intercept your google searches, edit the page to add it's own results, and return the page to your browser. And this isn't that hard with a Safari plugin to interface SpotLight and google, matter of fact, I might just go write one.