It seems very intuitive to me that being very good at predicting someone's decision (probably by something like simulating the decision-process) is conceptually different from time travel. Plus, I don't think Newcomb's problem is an interesting decision-theory question if Omega is simply traveling (or sending information) backward in time.
This is intuitive to me as well, but I suspect that it is also wrong. What is the difference between sending information from the future of a simulated universe to the present of this universe and sending information back in the 'same' universe if the simulation is identical to the 'real' universe?
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
(I plan to make these threads from now on. Downvote if you disapprove. If I miss one, feel free to do it yourself.)