All improvements to comment management outlined in this post completed and now available in source control, so if you wish to give it a test drive I really interested in your feedback. This includes both Disqus and reCaptcha integration (credits go to Hamish Graham and Filip Stanek respectively. The plan is to make it finalized and available for download as service pack or optional update in the next couple weeks. By then, there are going to be testing, refactoring an clean up but hopefully no major changes.
To enable reCaptcha, you’ll need (obviously) update from latest source code (1.6.0.5) and then go to extensions/settings and setup reCaptcha from there. Once extension enabled, you should see reCaptcha added to comments form. You might need to refresh or clear browser’s cache if you can’t see it right away.
Disqus can be turned on by going to admin/comments and selecting “moderated by Disqus” option. Both require you set up an account on there web sites and provide application key that you have to enter in the settings. It is free and, in my experience, pretty painless.