Shannon,
I think you will encounter some crowds still, as some schools may have an early spring break. However, because it is so early in the month I think there won't be too many schools on break just yet, so I would not expect the crowds to be unmanageable.
Planning your days and doing some research will go a long way to making your trip sucessful no matter how busy the parks are, so you're ahead of the game in that regard. A few thoughts:
-Plan out which parks you'll be in on which days and make dining reservations early. Try eating at off-peak times of day so you can avoid crowds.
-Hit the parks early in the morning. They are far busier in the afternoon, which is a great time to go swimming or take a nap. Parks will be open later at night, so you can easily head back out again and enjoy a thinner crowd at night.
-Consider avoiding the park with Extra Magic Hours (EMH) each day - many people find those parks to be more crowded, so the other parks are easier to navigate.
If you're really concerned about crowds, check out
www.tourguidemike.com. It is a subscription service that helps you plan for peak attendance periods at Disney World. It's not free, but I've heard many people say it's worth every penny to have a stress free vacation even in the midst of a very busy season.
Good luck!