How would that be different from today? Pin Skype to the side in "tall strip mode" and have the desktop as your main "app". Or do you mean doing that with multiple Metro apps?
If you only use a few applications that is fine. If you have multiple monitors and use more applications at the same time, it is much better to have the ability to arrange the windows in whatever way works for you. Now we are forced into some bizarre pre-Windows 3 mode where windows can't overlap etc. IMO it is a step back. How is it possibly a step forward?