He once posted his first message to Satoshi on the Bitcoin Foundation's forum, but I can't find it right away. I don't know if he ever kept track of all the messages, though.
All
bitcointalk forum posts of Satoshi:
https://bitcointalk.org/satoshiposts.txt.gzEdit: also, please keep in mind that conversation is private, I wouldn't expect someone to just publish it. In fact, without Satoshi's explicit consent, that would be rather rude. And it's highly unlikely that Satoshi will just pop up and say "Hey, here I am, go ahead, release it!"