This is very sad news. One thing I will remember from his NFL Films appearances was that he always demanded perfection, just like a football coach should.
You have to wonder what would have become of Montana and Rice without his West Coast Offense.
There will likely never be a guy with a "coaching tree" like Walsh, with many, many assistants not only later gettting head coaching positions but also having success.
And his Super Nintendo game Bill Walsh College Football was pretty fun.