Here's an article from the Wall Street Journal about the increasing difficulties for parents flying with children.

Luckily, my selected seats have never been reassigned by the airlines, though I'm pretty obsessive about checking my seat assignments periodically before my departure date to make sure that they haven't been changed.  And when I fly Southwest, I also set an alarm for 24 hours before the departure time to make sure to check in as soon as possible so that I can board the plane earlier.

One particular bone to pick with the article - it mentions that one reason why airlines are less baby-friendly is the lack of microwaves to warm up bottles (though it notes that flight attendants can still warm up bottles with hot water). Who warms up bottles with a microwave? That's a very big no-no. Which reminds me, don't assume that the flight attendant knows how to warm up your bottle. If you ask a flight attendant to warm up a bottle for you, clearly specify that the bottle should come to room temperature, no hotter. I had a flight attendant once warm up a bottle to a scalding temperature.