In the fancy new design, the menu in the top right of the page (Questions/Tags/Users/etc) has boxes that highlight when you are on that page. It is suggestive that the whole box is a clickable target.
However, in fact only the words are clickable, so this is a false affordance.
Please make the entire area hoverable/clickable.
i.e. I should be able to change to the Tags page by clicking where the red cross is.