I'm a bit into statistics, so here's what my thought is on how this should play out.
Do it the same way Amazon is doing it. Display an average in the overview, and then the number of votes for each rating in a bar graph. This will quickly reveal ballot stuffing and give interested players a very good impression. If some people think the realm is great and some think it sucks, it's likely that the realm is being controlled by a group of players who are having all the fun. If votes are distributed evenly, it's more egalitarian.
In most of the statistics I have done publicly, I have always insisted on publishing the actual numbers in addition to averages.
ooo... bad idea.
Well, bad idea with low numbers. I'd say publish it as "Less than 4" then publish numbers above 4. Or 3, or 5, or something like that. See my point here? Making it so that maybe ONE person has cast their vote for something carries identification problems. It makes an anonymous system no longer anonymous.