First I must say that this Anti Slog API is awsome!
I did however noticed an easy improvement; a user/blogname with more then 2 numbers in it is probably spam.
This signup was manual at my site, so it might not get scored 100%, but at least 80 or something…? Now it got 0%.
A blog with a name longer then 15 chars might also score some points, not so many people would
want such a long name on its blog.