If you know that Omega came to a conclusion about you based on things you wrote on the Internet, and you know that the things you wrote imply you will one-box, then you are free to two-box.
Edit: basically the thing you have to ask is, if you know where Omega's model of you comes from, is that model like you to a sufficient extent that whatever you decide to do, the model will also do?
Ah, but the thing you DON'T know is that Omega isn't cheating. Cheating LOOKS like magic but isn't. Implicit in my point, certainly part of my thinking, is that unless you understand deeply and for sure HOW the trick is done, you can expect the trick will be done on you. So unless you can think of a million dollar upside to not getting the million dollars, you should let yourself be the mark of the conman Omega since your role seems to include getting a million dollars for whatever reasons Omega has to do that.
You should only two box if you understand...
EDIT: I see by the karma bombing we can't even ask. Why even call this part of the site "discussion?"
Some of the classic questions about an omnipotent god include