Jim,
Actually this is a bug. You were not supposed to get comment moderation email, and didn't realize that they were being sent to the article author, besides the admin...
This should be fixed now, please let me know if such emails keep arriving.
Unlike other forms of collaboration at iModeler, article commenting is open to anyone - an occasional visitor can leave a comment to an article even without having a valid iModeler account. Our intention (at least at this point) is to keep the commenting open, since this will undoubtedly increase the amount of visitor input you may receive to your articles over time.
However, the web is full of spammers, and we do apply multiple measures to keep them away. Besides employing an automatic (and let me say rather advanced) spam filter, we adhere to the rule that the first comment from any user is held for moderation before becoming visible at the site. Hence notification emails on "some" comments only. But, as I said, these were intended for admin's eyes only.
Hope this helps /M.