For Laughs
Ask, "Do you hope the baby looks like you or your wife?" Loaded questions like these are always good for giggles. If the dad-to-be wants the baby to look like himself, the guests will laugh at his shameless lack of modesty; and his wife might just attack him with throw pillows. If he says he wants the baby to look like the mom-to-be, guests will chuckle at his shameless lack of good looks.
For Nostalgia
What is your fondest memory of your father? When a man learns he is to become a father, he undoubtedly thinks of his relationship with his own dad. Giving the dad-to-be this chance to stroll down memory lane reminds the expectant father how important it is to be a great father himself.
For Sentimental Value
If you were going off to war and could only leave one thing for your baby to remember you by, what would it be and why? Answers to such a question tend to run the gamut -- my favorite chess set, my dad's advice about saving, my wife and best friend forever "insert name." And they also tend to make the dad-to-be break out in tears, which is fine because men have sensitive sides too.