I think this adding "The Useful Idea of Truth" is the most important change. The first post is the most important, and even if you want to call it "Sequences 2006-2009," you should still open with a post designed not to be informative as much as to catch readers. I think the "The Useful Idea of Truth" is the current best option. What would be even better would be if Eliezer wrote a new intro.