As already written in my Stop supporting IE6 article I hoped for IE8 supporting media specifiers in CSS @import statements. The benefit would be to lock out IE6 and IE7 from seeing the CSS definitions without using proprietary IE conditional comments. Fortunately Microsoft really did it, they support this syntax in IE8!
So if a website is going to drop support for IE7 (which may be a good idea because IE7 is still a pain-in-the-ass when it comes to web standards) then it can be done like this:
<style type="text/css"> @import "common.css" screen; </style>