hello
I made the plugin.
http://2046.cz/freestuff/content-character-count-live-plugin.html

on the way to WordPress repository.
I changed the code slightly so it just counts the characters. But what is the major change is that it count the words right when the page is loaded, no action necessary. Your version counts it only when someone starts to type.

Don’t wary you are mention in the code and the description as well.