Congratulations, Dan !
I´d guess I have at least 10 years to go before I´ll be a grandfather. But then I expect to have a few from my four children.
In my line of work I see a high degree of involvement from grandfathers/mothers. It seems it is the perfect position. Cuddle up with the baby in your lap, when you start to smell it - just leave to mother...
Most of all I think one feels a tremendous ego pride looking at a grandchild - that is ME, two more generations ahead. I will survive long after I am gone. I did good!