Dave's right ... "/admin" are the admin pages for the "/" subsite, not for the site at large. We need to preserve the distinction.
Now ... a better UI that steers you to the right places is needed, no doubt about that. Given the better UI the confusion as to what's what should go away. And a better UI's being talked about for 4.6 (or at least it's on everyone's 4.6 wishlist).
