It's important to keep in mind that the Metro apps work better on smaller screens than normal desktop apps. They hide a lot of the UI when you don't need it, so there's much more room for actual content. I wouldn't want to run, say, IntelliJ Idea on a Surface, but for many other apps, the screen size is not much of an issue. Also, you can dock the Surface when you're on a desktop, and use a larger screen.