From my limited experience on the site it seems that questions in some categories attract more votes than others regardless of (my opinion of) their quality. This may be because there are many more people with an interest in that area, so there's a larger pool of people likely to vote. This seems to lead to fairly basic questions that everyone has a view on attracting scores of votes, while niche questions attract a handful.
Another possible reason would be if there are any philosophical differences between sub-groups. For instance I'd be interested in seeing if people tend to vote differently between .NET and Java. Do Java users vote more or less? Do answerers in each category vote more or less?
So now the questions. Is it possible to see average votes by tag? Can we determine the number of people "active" in a tag?