I like his causal answer to Newcomb's problem:
In principle, you could base your decision of whether to one-box or two-box on anything you like: for example, on whether the name of some obscure childhood friend had an even or odd number of letters. However, this suggests that the problem of predicting whether you will one-box or two-box is “you-complete.” In other words, if the Predictor can solve this problem reliably, then it seems to me that it must possess a simulation of you so detailed as to constitute another copy of you (as discussed previously). But in that case, to whatever extent we want to think about Newcomb’s paradox in terms of a freely-willed decision at all, we need to imagine two entities separated in space and time—the “flesh-and-blood you,” and the simulated version being run by the Predictor—that are nevertheless “tethered together” and share common interests. If we think this way, then we can easily explain why one-boxing can be rational, even without backwards-in-time causation. Namely, as you contemplate whether to open one box or two, who’s to say that you’re not “actually” the simulation? If you are, then of course your decision can affect what the Predictor does in an ordinary, causal way.
Simple but misleading.
This is because Newcomb's problem is not reliant on the predictor being perfectly accurate. All they need to do is predict you so well that people who one-box walk away with more expected utility than people who two-box. This is easy - even humans can predict other humans this well (though we kinda evolved to be good at it).
So if it's still worth it to one-box even if you're not being copied, what good is an argument that relies on you being copied to work?
Scott Aaronson has a new 85 page essay up, titled "The Ghost in the Quantum Turing Machine". (Abstract here.) In Section 2.11 (Singulatarianism) he explicitly mentions Eliezer as an influence. But that's just a starting point, and he then moves in a direction that's very far from any kind of LW consensus. Among other things, he suggests that a crucial qualitative difference between a person and a digital upload is that the laws of physics prohibit making perfect copies of a person. Personally, I find the arguments completely unconvincing, but Aaronson is always thought-provoking and fun to read, and this is a good excuse to read about things like (I quote the abstract) "the No-Cloning Theorem, the measurement problem, decoherence, chaos, the arrow of time, the holographic principle, Newcomb's paradox, Boltzmann brains, algorithmic information theory, and the Common Prior Assumption". This is not just a shopping list of buzzwords, these are all important components of the author's main argument. It unfortunately still seems weak to me, but the time spent reading it is not wasted at all.