If you want this post to be discussion about the copyright status of posts on LW, then you should change the title. I expect that a lot of people who would be interested in commenting on that issue might skip over this post because the title gives no indication of the actual topic.
You obviously cannot retroactively change the copyright status of already published posts without the express consent of their authors, but I'd support a move to add a text saying "by pressing submit, you agree to license your post under [some CC license]" to the submission form. Or possibly an option to choose under which license you wish to publish your post, though that would more work for the site programmers.
Also, I hereby declare all of my past and future posts on Less Wrong to be licensed under CC-BY. EDIT: No wait, I can't make such a declaration, because part of my posts are written for MIRI, who owns the copyrights according to the work-for-hire clause in my contract. I'll try to mark these posts somehow, but ask me if you want to be sure.
I just want to draw attention to the following bit of Kaj's comment, which seems like it should be really obvious but Rick's original post seems to indicate wasn't obvious to him:
You obviously cannot retroactively change the copyright status of already published posts without the express consent of their authors
You can "propose [] that all content on the site be subject to the [CC-BY] license", but you can't actually bring that state of affairs about.
If you've been following the announced partnership between LessWrong and Castify, you'll know that we would like to start offering the promoted posts as a podcast.
So far, everything offered by Castify is authored by Eliezer Yudkowsky who gave permission to have his content used. Because promoted posts can be written by those who haven't explicitly given us permission, we're reluctant to offer them without first working through the licensing issues with the community.
What we propose is that all content on the site be subject to the Creative Commons license which would allow content posted to LessWrong to be used for commercial use as long as the work is given proper attribution.
LessWrong management and Castify want feedback from the community before moving forward. Thoughts?
Edit: EricHerboso was kind enough to start a poll in the comments here.