Better would be to predict that the comment will have, say, between -10 and 0 karma. Would the audience who dislike this type of comments downvote to hurt the author's karma, or upvote to frustrate his prediction?
(I am not going to do the experiment myself - the first time it is slightly amusing, the second time it would be annoying. But if somebody doesn't mind being annoying...)
We're really good at this sort of group coordination: -20 karma for sure :)
I predict, with 50% confidence, that this comment will have between +1 and +4 karma at 9 pm PST on 6/2/2011.