It would be absolutely lovely if you would force-install IE9 alongside lower versions, and use IE9's rendering engine from lower versions if a special meta tag

It would be absolutely lovely if you would force-install IE9 alongside lower versions, and use IE9's rendering engine from lower versions if a special meta tag would be present in the webpage. That way you get all the backwards compatibility anybody will ever want, and we can finally forget about IE6&7(&8). Cheers!