You can administer both Firefox and Chrome with group policies. I know because we do, having supplanted IE6 as the corporate standard with Firefox 3.x last year (and testing Chrome 6 right now). It was far easier to install an alternative browser than it was to ensure an IE upgrade wouldn't break some legacy systems no one could support.

<edit> This will be more helpful: http://store.frontmotion.com/FirefoxPackager/ http://www.google.com/chrome/eula.html?msi=true