The backbone of the Diseased Sons is hordes of Plaguemarines. Seven squads all carefully numbered and painted. The squads evolved and expanded over time due as much to rule changes as anything. Many models specifically all my heavy weapons troopers were made illegal and so I stripped most of them and will be repainting them as Chaos Undivided troops at some point.
After the release of 4th Edition and the end of my MBA, I used some of my time to make the squads look better and be more useful on the table top. But before I could get all this done, another new Chaos Codex is set to come out. The final step was to be painting dedicated Icon Bearers and Champs armed intelligently for the latest rule sets. Now I plan to paint a few more Nurgle Renegades with Heavy Weapons even though I stripped some from this very army. Then sometime in 2008 I will declare the Diseased Sons done and do some undivided or Khorne and Slaneesh troops. Even with the new rules supposedly favouring them I have zero plans to paint 1000 Sons.