Suggestion: superuser.com should forward to superuser.stackexhange.com or something with stackexchange in the name, and should very-very-clearly be branded as part of the SE family.
I eventually figured out that it was, indeed, part of SE (right?! :) but, given all the fake-SE/SO copycat sites out there, it'd be nice to at least see stackexchange.com as part of the URL.
I love the whole SE family thing but, given that 99.44% of my usage is on S.O., when I go to a different member site, it'd be nice to know that I'm "in bounds" and haven't strayed to one of "those other guys" and am about to give them my account credentials, etc.
(Same suggestion for all the other SE family that doesn't have SE.com in the url.)