It would be nice if you could prevent people you have ignored from commenting in your threads at all.
At this point in my thinking, I am against this. I think the ignore feature is good and needed, but needs to be tweaked.
Before giving OPs the ability to censor posters in their thread, I think that the power to ignore should be given to individuals. I like the idea where when you ignore a user, their comments are completely blacked out to you, universally. Wherever they appear on the site, you can see replies to them, but not the comments themselves.
I think that if you are truly disturbed/offended by a user's comments, they should only be blocked to you. Let other users make that determination for themselves. Furthermore, I think that if you are going to take the extremely drastic step of blocking a users comments, you should truly not have access to them. Users are going to think long and hard, -or at least be given pause, when they can see responses to the blocked comments but not the comments themselves. The conversation may continue to go on without them, but I think that if you are allowed to take the step of blocking a user's comments, you have to be mature enough to accept true disengagement. You shouldn't have the option of chasing down that user's comments through some other, less effective blocking mechanism, and getting drawn back into the tollfest or the heated argument. I think removing the comments universally only for you gives the ban the gravity it deserves.
Because censoring comments simply because you disagree with them is so universal (again, see Reddit's down vote usage by basically everybody on the site), I'd like the see the ban be universal as well, as mentioned above. What this does is hopefully avoid a situation where in the heat of the moment or argument, you just ban a user's comments in a thread after declaring you've done so. If the ban is localized to the thread, this will just have the effect of shutting down engagement with people who's views challenge yours, or who's tone often grates you, despite the fact that they may also be great contributors in other ways or threads. kleinbl00 is a good example (for me). His posts are prolific, often challenging, and there is no denying that he is a great contributor with a definite point of view and passion. On the other hand, I find some of his posts just downright appalling in tone. If I had a button that could ban him in a single thread, I would have been tempted to smash it many a time. If the ban was universal, it would give me more than pause....is this discussion/argument/whatever in this particular thread so egregious that I need to deny myself access to this person's thoughts on the entire site? Do I value the sum of this person's content so little that that would be a decent trade off? In the case of klein, the answer would be an easy no. Again, give the ban the gravity it deserves.
These thoughts are for the current implementation of Hubski. Depending on what mk has in store regarding user's hubs as personal content platforms.....well, that would change the dynamics quite a bit. Content publishers have different moderation needs. I'm coming from the angle of Hubski as a place for thoughtful discussion primarily. I'm most concerned with making sure that censoring doesn't weed out challenging discussion as well.
Edit: Another thought on ignore. If you ignore someone, but can still run into replies to their blocked comments, it sort of serves as a reminder that you've blocked this person. You can infer the quality of the discussion the blocked person is engaging in by seeing the reply. Maybe this will serve to reinforce your decision, or maybe it might, over time, give you pause and have you reconsider your ban. An interesting mechanic would be that if you decide to unblock somebody that you've blocked, there is a delay of 48 hours or more, -enough time to prevent people from unblocking just to jump back into an argument or what have you. It should be a thoughtful and genuine desire to want to see the person's content again, -as thoughtful as blocking them should have been.