When you change your email address in your profile, until you've verified the change, it LOOKS like you're normally logged in, except private message numbers don't appear in the dialog ("You have <blank> new messages"), and you can't post or reply. But other than that, it looks like everything is normal! I was freaked out a bit until I realized what it was. Maybe a nice little "AWAITING AUTHORIZATION AT NEW EMAIL" notice in a prominent position would help.
