It shouldnt be too bad as its outside the main school holiday time. DD finishes on 14th for the 2 week Easter break. As Easter is so early this year some schools are having their break later in April but I cant see any having it earlier.
However saying that I think there is a kids under 12 free offer on at that time
Double check if this is the week when the kids go free and an extra night free offers are running, we have been twice during this time and it's busy, especially noticeable at the weekends. If it's just the Kids Go Free it shouldn't be too bad.
Expect queues of 30-50 mins for BTM, Phantom manor, POTC, for us we've always noticed that the Fantasyland rides have the longest wait times, I recall seeing a 90 minute wait for Snow White
I wouldn't hesitate to go again around this time though, the extra days we could afford due to the offers gave us plenty of time to do everything. The weather is pretty changeable though, it was bitterly cold with sleet and snow in 2004, in 2006 it was bright and sunny but chilly and last year I seem to remember people saying the weather was unusually warm, although that all changed 2 weeks later when we visited at the end of March.