I visited Disney the week after Easter several years back. The Monday was easily the busiest day. We went to Animal Kingdom that day and it was a madhouse. However, getting their early, and taking advantage of the Fastpass saved us. Test Track Fast Pass at Epcot filled up really quickly and unless you used the single rider line (which I did) it was a 3 hour wait. I know it was a while back and things may have changed a bit. Just be prepared for it to be busy and be hot and humid.