It's ugly, but it's here. If anyone can help make it look better, please go ahead. My thought on this is that it will go at the bottom of a wiki entry. It needs to have a boilerplate something like this:
{{Size|
wiki_statistics_URL = No
| wiki_size = Number of valid articles
}}
Let's test it out and see if it works.
Then, we need to incorporate the Category:Size calculations into it somehow. I don't know if the code can do this or if categories will have to be put on by hand. Does anyone know?