As for how he supports himself and is able to make the time to code is a mystery to me.
http://github.com/why/potion/graphs/punch_card
Looking at his commit patterns, it's throughout the days of the week, even though the bulk of it is at night. But it's reassuring to see that even _why stops for dinner, and the reason why the rest of us aren't as productive is because we're not as consistently hacking away as he is.
As for knowing more about him, I'd say you'd probably learn more about him reading his code than digging up things like his real name.
I watched his talk at ART && CODE (http://www.vimeo.com/5047563) and it was full of some awesome jokes at his expense. I think self-deprecation is the best of character traits.
I am curious what he does for money, though. My ultimate goal is to have enough in the bank to solely hack on open source stuff for the remainder of my career.
oh, and thanks to raju for submitting the link; I last checked hackety.org about two weeks ago and it was down then. it's nice to see that hackety.org is up and running again.
That nobody's outed him is a testament to his greatness.
It's not secrecy as much as it's mystery