Long time passed since he last posted in here. Why? "Busy"? I don't think so. He was active when bitcoin needed support but since the slashdot...
Also, it seems has knowledge in many areas, especially economy. He doesn't act like the average human. Not taking advantage out of his creation, leaving without telling anything. Is he even a single person or a group?
How can someone create something so great and not stepping out to get the credit?
I think Satoshi Nakamoto refers not only to a single person but a group of people who are probably expert I.T. engineers. Knowing their identity can bring them to possible risk that is why until now we don't have a concrete information about them. Surely, they are enjoying all their profit today without knowing by anyone.