If you spend any time at all reading about history of Bitcoin and other related currencies, it's clear that Satoshi was a cypherpunk. And at least an active lurker, if not a well-known participant, in the cypherpunks mailing list during the 1990s and early 2000s. Just look at the sources in the bitcoin paper. Satoshi cites lots of cypherpunks, and not many mainstream academics. The code borrows time-stamping ideas from Usenet and takes inspiration from command-and-control architectures of IRC botnets.
The pieces of the puzzle are:
- (1997) Adam Back's hashcash proof of work system
- (1998) Wei Dai's b-money
- (1998-2005) Nick Szabo's writings about git gold
- (2004) Hal Finney's reusable proof of work (RPOW)
Satoshi brought these ideas -- cypherpunk ideas -- together to make Bitcoin, not the ideas about improving Chaumian blind signatures and anonymous e-cash that were being discussed in the academic crypto literature of the time. Remember, cypherpunks (and others inspired by Tim May's crypto-anarchy) have a long history of communicating anonymously. Anonymous remailers and pseudonyms were expected on the list, so it's not unusual to see Satoshi Nakamoto come out of this tradition.
There are probably people that know who the identity of Satoshi Nakamoto, but they're not going to tell. They're cypherpunks, after all. And if Satoshi stays anonymous, it just means that everything is going exactly as planned.