Satoshi's final statement
I've got an answer on Reddit:

It's likely to have been written in a PM or an email to some developers, and it seems that Mike Hearn (BitcoinJ) was the one who published this statement:


  Mike Hearn - February 25, 2013, 12:48:54 PM
  
  He communicated with a few of the core developers before leaving. He
  told myself and Gavin that he had moved on to other things and that
  the project was in good hands.


Source: Re: Could Satoshi come back and tell us what he/her thinks about the block size?

Still, if someone has additional information I would be glad to know about.