I get it. I just don't think I would use it as you never know what will pop up. I don't even collapse the sections I'm not using/interested (lack of better term).
It sounds like a useful feature. Honestly, I don't use the "new posts" button. I just go to the areas that are in my interests or where I feel I can offer reasonably sound advice. Where my interests and not knowing good answers collide, I'll use the "watch" button without commenting.