Is this going to be used ultimately to rate posters (kind of like the Apple site for one example)?
That's the "reputation system" question. I continue to dislike the idea that being a member is a competition (even though for fun I track statistics on who posts the most).
How is abuse of this going to be addressed?
See my
earlier post.
If all its used for is the post itself, I dont see any value for this.
That's been addressed too. Putting the post-vote system in place necessarily has to precede using the data to provide other new features.
What are MRs (Arns and the other Gods) thoughts on what they want to do with this?
It hasn't been decided, but it could include ways to find or highlight highly-rated posts. I hope there's a way to use the feature to find the best answers in technical/help threads. Perhaps there's a way to turn post votes into thread ratings; I'm not sure about that.
I do think there should only be "ups", but the icon could be a checkmark. When you click it some subtext would appear below/next to it. Something like "You liked this comment" or "You agree with comment" or "This comment was helpful".
Those are both worthwhile ideas. Most uses of the votes would be to identify good posts, not single out bad posts, so positive votes provide the more useful information. The data is there to tell you how you voted so feedback on your own vote seems like a nice touch.
Perhaps allow a post that receives a certain number of dislikes to be "hidden" from a general view unless someone decides to view it by clicking on a link.
I wouldn't favor an automatic system like this. Since you can't tell the reasons for people's votes, it could eliminate less popular posts in debates, leaving you unable to follow the discussion. And if all visible posts agree with each other, why have a discussion at all?
If there was such a system, I think it should be entirely voluntary, e.g., you can ask to see only certain posts based on votes. But I think the back-and-forth nature of discussion, with users quoting and building on previous posts, would make this less useful than it sounds. Perhaps it would be worthwhile having a User Profile setting to hide the voting system completely from users who aren't interested in using it. But we have to put our programming resources where they will do the most good.
Like some of the posters here I can think of ways to slice and dice the data, (what threads in a given forum have the highest percentage of positive-rated posts?) and ways to collect other information (rating posts by multiple criteria, e.g., "helpful") but the system has to be kept simple to work in practice. That's one argument in favor of having the arrows in all forums. But perhaps we'll learn that voting does more harm than good in certain forums, e.g., in political discussions.
Remember that forum features are designed to provide benefits to the overall membership. Your comments in this thread help us find the best ways to do that, so thanks for sharing your thoughts.