Comment spam happy ending
This however means that Drupal 5 users in a similar environment (high PageRank and unregistered comments) may still be affected. The filter module may help, but will also not help in the PageRank front as it may not differentiate normal links and contributed links, something Drupal 6.3 will do out of the box as intended.
As a result I have not seen the surge in comment spam anymore. I still received a few which is most likely the fallout of my encounters with the spam forums.
For those who missed the whole thread, here are the older posts once again: