Steve Jobs seems to have turned a new leaf and is sending more emails.
I theorize that he has a personal assistant who releases him a few select emails a day to reply back to.
And so it's another way for Apple to disseminate information to the world. The thing is, it works really well for them as it shows that even for one of the world's biggest technology companies that they are able to maintain a strong company focus (and ecosystem) where one man can speak freely on behalf of the whole company.
This is a good blog to follow --> Emails From Steve Jobs