[roc]

Links have more subtle affordances that make them stand out from web text and few people have a problem navigating that.

Microsoft's problem isn't inherent in having a 'flat' design. It arises because of their alternately uniform (outlook), and seemingly arbitrary (metro desktop), color, contrast, layout and font-weight choices.

They could conceivably shift to a design-language where those attributes could be used to hint at interactivity at least as well as a big shiny buttons.