Having kids has been a great change in my life. My kids are 4 and 6 now and I'm loving being a dad. I can still work long hours, but I split the hours to spend time with them. I don't have the time I'd like to have to dig into new technologies, new tools, etc, but I feel I'm a good dad. Starting to do some science experiments with my kids which is very cool.
What has worked for me is to get an early start in the morning so I can cut off work at a decent hour. Then I often will put in hours after the kids go to bed. Doing this I can still put in fairly long hours. Important thing is to review your goals and milestones and make adjustments to the time required to hit them. If the schedule was created assuming 60-70 hours a week, you will need to rethink the deadlines.
On the family front, one thing that has worked out really we for my wife and me is that we each have one night a week free, where the other is responsible for the kids. This one afternoon/evening is a nice relief. I use it to go grab some drinks with friends, play golf, hack on a project, watch a movie, etc. We both find that we are better parents (and spouses) when we get some down time.