It seems that if you look at the column on the right of the page, you can see upvotes and downvotes separately for recent posts. The same [n, m] format is displayed for recent comments, but it doesn't seem to actually sync with the score displaying on the comment. This feature only seems available on the sidebar: looking at the actual comment or post doesn't give you this information.
Thanks, whoever did this!
MediaWiki captchas are terrible and literally worse than useless (keep many humans out, fail to keep spambots out). reCaptcha is a little less worse. But if they have something that works for wiki spam, please be sure to post it to mediawiki-l! Thank you :-)
Protecting one specific Wiki from spam and protecting Wiki's in general from spam are two different problems. Spam security by obscurity works for a single Wiki.