What is the shape of the hole Less Wrong used to fill? What is the problem that needs solving? In a nutshell, I'd say it's "current inability to have a healthy, online discussion in order to build and improve our shared understanding of the world\." 1 At Arbital we think the key parts of this problem fall roughly into three categories:
I think this section conflates two things: 1) the role LW used to play, and 2) the role ultimate-Arbital will play.
I think 1 is a subset of 2.
In particular, I don't think LW had solved the problem you describe here: "If someone wants to catch up on the state of the debate, they either need to get a summary from someone, figure it out as they go along, or catch up by reading the entire discussion."