It'll never happen. The moment Satoshi shows himself on here, the price will crash. Fears of him selling off his stash will spread through the community.
I think the identity of Nakamoto is really a plan of whoever invented it. The more it become mysterious the more mouth will be open to talk about this. Pseudonym makes him/her/them popular. I think wether he/she/they show up or hide it will all be the same because bitcoin established itself to the market so it didn't have some impact in the price.