Today google announced an initiative to combat the "comment spam" currently plaguing the blogosphere (and, in fact, much of the internet). The "solution" (to add rel="nofollow" to all links - to prevent google from indexing the spammer's site) is simple and has some interesting effects as noted by robert scoble. while it's probably not a solution that will completely eliminate the problem, the number of people already behind the initiative is rather impressive. so impressive that I figured drupal should join the fray.
So, as of moments ago, drupal also supports rel="nofollow" .