Hey! What a great plugin! I love it!
May I suggest an addition? It would be great if we could specify the link title for each taxonomy. I'm using custom taxonomies with custom post types and when I hover the mouse over a custom taxonomy link, it displays "3 topics" or something like that. Can it be adjusted, so it could display "3 books" for instance?
Another thing to consider would be an option to be able to set the widget to display only children of the current taxonomy (unless it's a top levbel taxonomy). So when I have a hierarchical taxonomy, first, it would display only the top level taxonomies. Then, when I click on one of them, it would display only the child taxonomies of the current taxonomy.