Julia is the author of the recently-linked article Are Intuitions Good Evidence? and many other writings. I know less about Jesse, but I can say a bit more about Julia. She co-hosts the Rationally Speaking podcast with philosopher-biologist Massimo Pigliucci. She writes quite a bit about becoming more rational, dissolving Big Questions, and wanting to change your mind. Her video on different definitions of 'rationality' distinguishes Hollywood rationality, epistemic rationality, and instrumental rationality. She explains the mirror paradox ala Gary Drescher in Good and Real. She blogged Harry Potter and the Methods of Rationality.
I suspect Less Wrong readers will enjoy Measure of Doubt, and will find it a useful place to send people who don't have the patience to read the Less Wrong Sequences and long posts about Bayesian updating and the relevance of universe-simulation arguments to decision theory.