DD will just be 4 when new baby is born. Live in burbs and never take her stroller in the car, but we do use the stroller a fair amount for walks into town, to the park, etc. Should I get a double stroller? If so, what should I get?

It depends on the situation - at a place like the Bronx Zoo or Disney it makes sense, but on a day-to-day basis they usually aren't necessary. We live in Manhattan, and other than the Bronx Zoo, 4 y/o DD hasn't used her stroller in about 6 months. We do take the bus more than we did when she used the stroller regularly, though (it's easy for me to walk 20 or 30 blocks pushing the stroller, not so easy for me to muster the patience it takes for DD to walk that far).