I psted this to another thread as I am, too, going to be there the last week of April. It looks to be a great week to be going. Read the post carefully and goto the website link I've provided:
This past Sunday thru today is inline with every other year. Look at the following webpage as it is your very best reference as to what to expect while you are there:
http://www.touringplans.com/BestDays.htm
The crowds during these past few days rank up there at 6-8 out of 10 which is pretty nasty.
The last week of April looks good as this is when the crowds finally thin out from the 4 rank to the 3's. I think it will be very manageable. I've got reservations at the resort April 24th (only crowded day) - April 30th. In 2001 I was there the last week of Februaury and was hit with crowd levels of 5. While very manageable at this level, they were somewhat annoying at times.
In 1993 I was there in early May and experienced the least crowded times I had seen since vacationing at the resort. Those days rank in the 3's so I am hoping for the same decent experience this time around.
Rule of thumb....avoid any park with the extra magic hour as almost all on-site resort guests will show up on that day. Those people alone could reach upwards of 25,000 people as there are just over 25,000 rooms at Disney hotels.
-J