It is sad to see Bill go.  I've been in the software business a long time, and I have definitely gone through a few phases in my career ( liking Microsoft and not liking Microsoft ).  Bill Gates has been one of the most thought provoking figures in the industry for the past couple of decades.

Bill moving on, kind of seems like a sign of the times.  The software industry is maturing.   We are starting to come to terms with the influence that our applications, frameworks, and systems actually have in our world.  We've been busy building them, and having a lot of fun doing it.  Now we're getting older, and realizing what all of these capabilities mean in real terms, and how they can truly be used to make a significant positive impact in the world, and future generations.

Best of luck, and best wishes, Bill!