1) Things that are off topic for HN.
2) Commentary from people who meat some sort of HN criteria (i.e. able to make reasonable statements and arguments).
Also, it turns out that a good number of people are interested in politics articles and a good number of people here get annoyed with politics articles.
The proposed solution seems to cover both problems. I'm not sure if it will work, but certainly the issue it is trying to address is real.
But I, and obviously others like me, see it as a community of people who I enjoy interacting with. As such there are going to come rare times when I want to seek that community's opinion on a certain topic because I value the opinions here so much.
So for me, it's not sufficient to say "go somewhere else" because it's the community here that I want to interact with. And I don't see anything wrong with that as long as its done in moderation.
Based on that conclusion I personally don't think this is a discussion worth having. PG has shown he's willing to kill topics if he feels the "off topic" level is too high. So as long as people who get their items killed don't take offense I think we have the perfect ecosystem to keep off topic items at just the right level.
(Though I personally wouldn't object if an "Off Topic" section of HN was added either)
Any suggestions to create an off-topic board is not a solution. These are mostly populated by those who would come to the site based on politics and nothing to do with what Hacker News is about.