We went for our disneymoon the week leading up to Easter(2004). It is crowded, but hey your at Disney. The weather was great. Don't worry so much about the crowds and as long as you have a plan and fast passes, you are good to go...
We've been in April a couple of times as that is when the kids are off of school. It really isn't that bad. Plan your time wisely and it will all be good!!!!!