Ok, so, what if all traditional programs are written in the Metro style as a Metro app or more appropriately a M$ app? That would solve the whole problem, wouldn't it? I believe this is what M$ has in mind with this drastic change of an OS called Windows 8. All programs will eventually be M$ apps. They are being written as you read now. Imagine the possibilities here. They can totally do away with the desktop all together. One will open an app in stand alone window or -> Open another with an option to snap along side -> Open another app with the option of a 3rd pane -> Open another for a 4th pane and so on. Just like the big screen TVs with multi-pane viewing a zillion channels in live time. Or perform on multiple monitors. (I know there's a long way to go so far as snapping and multi-monitors, so I don't want to hear the slack.
I think this will be worked out in the future)