No, I don't think I've ever seen any official support for customizing themes. There is the Hot Dog theme for SO (http://meta.stackoverflow.com/q/34939/1288) that you might be able to use as a starting point for a custom user theme.
Sorry, should have been more clear. What I really meant was having things like the score, number of answers, etc, in nice big numbers next to the question.
Oh, not on the official site. I don't think that page is updated in real time, so the vote counts would be off by quite a bit for the hottest questions on each site. You might find an app on http://stackapps.com/ that uses the API though.
