Hi Angela,
I agree with Dan's response, but I'd also like to add that we've an better experience in managing comments by disabling Wordpress comments and installing Disqus to handle comments.
Previously we were running into issues where our sites were bombarded with spam comments, and it was hit or miss with Akismet. That problem has been virtually eliminated.
As far as losing comments, you won't, as you install the plugin and then export your comments to Disqus with the click of a button on the plugin settings page. You can then sync comments back and forth between Wordpress and Disqus as necessary if you decide to from one to the other.
Mike
