As i understand it, Google.org is not a separate non-profit organization. It's part of Google, and in many ways i will be just another Google engineer. But it does have a distinct mission, and compared to Google as a whole it is relatively young.
I owe my thanks to everyone who had comments and advice to offer as i was pondering this big decision. Having the support of so many wise friends helped a lot. I'm also grateful to many friends who are now at Google, for encouraging me to look into this possibility and for whatever good words they may have put in on my behalf to make this opportunity real.
I can't wait to start playing my small part in efforts to solve some of our biggest problems!