Comment forms on your website

I've got a complete rewrite of my website on my todo list for this summer.  Sure, I would have liked to do it earlier but it's a matter of finding enough time.  One of the things I'd like to do is to change from Etomite to WordPress.  I've used WordPress on several other sites, one of which isn't strictly a blog, and like it a lot more than Etomite.  I find it a lot easier to customize and maintain.

Switching to WordPress gives me the opportunity to enable comments on pages and posts, but I don't want them on every page.  I've got a pretty good collection of articles on my site and am thinking that comments on those would be a good opportunity for interaction with potential clients. 

Assuming that I keep up with watching for spam messages, does anyone see any downsides to having comment forms that I may be missing?  I'm sure there's a downside, but I can't think of any off the top of my head.