That's just the example for MacOS, the idea is to illustrate that you use the firefox_binary desiredCapability to indicate the alternate path. Mac surprisingly needs the binary inside the package; on Windows it's just ```foo\bar\blah\firefox.exe```.

There are example paths for all three platforms on the webdriver wiki, maybe I should add those as well? Any thoughts on how to document this so it's easy-to-understand?

See here, second table on the page: https://code.google.com/p/selenium/wiki/FirefoxDriver