Some of the resorts on Easter have what they call Easter egg hunts (plastic eggs) and a visit from the Bunny, and some also have arts and crafts. I believe BC has the hunt but not sure about SSR. Those hunts usually have huge numbers participating which often leads to some tempers flairing. Some of the buffet restaurants have an Easter brunch (for which if you have not already made ressies you are probably out of luck).
Other than that do not expect any special events. There are some Easter decorations, mostly hardly noticeable, and MK during much of the week has a bunny as one of the characters to meet and greet, but for the most part Disney does not treat the time different from other spring break weeks. Some hints:
1. MK is hugely crowded on Easter and often closes due to capacity (actually MK is hugely crowded everyday during that time but Sunday and usually the day before and after are worse than others). Huge numbers go to MK on that Sunday believing something special must happen there on Easter that they cannot see other days of the week. They are wrong. Nothing goes on at MK on Sunday that you cannot see other days. Other parks tend to have their lightest days for the holiday period on Sunday and the day before ("lightest" is relative -- still very crowded but lighter than other days of the week) so you might choose one of those on Sunday.
2. If you have not yet made dinner ressies for any sit-down (including buffet) restaurants that you intend to go to, do so immediately. Without ressies, you won't eat. True story: I was at the Crystal Palace on the Thursday before Easter waiting to sign in when a family of four in front of us got up to the window and asked to get in without a ressie and were informed it was heavily booked, and they asked, "Could you tell us when the next open time is to get a reservation?" The CM looked at the computer screen for a long time and then looked up and said, "Tuesday at 8:30."
3. Stand-by lines for any popular rides/attractions get to over two hours (three for Soarin' and Test Track) by 10:30 a.m. and they stay that way all day and evening. Fast-pass becomes a must but those run out for the day before noon. Even secondary rides/attractions get sustained lines of over an hour. Parks generally open earlier than usual during that time and early morning is your best bet to get on anything without huge lines and without fast-pass. However, during the parade (or during the first Fantasmic at the studios) lines might drop to no more than 40 minutes for popular rides and thus can be attempted then. Note, if you intend not to watch the parade be wherever you want to be during it an hour beforehand; otherwise you will not be able to get through parade crowds to get soemwhere. Also, after 4 and before 8, you can often find shorter lines for many attractions other than the real popular ones.
4. There are two Fantasmics nightly. For the first one, you need the dinner package to get in unless you want to line up an hour before or longer. The second one never fills and you can walk in at the last minute.
5. For the MK daily parade and first nightly one, people start occupying ideal spaces 90 minutes or more before. If you don't want to camp out for a long time just find some elevated place (e.g., porch of the Town Hall) shortly before the parade to watch.
6. Waterparks, unless it is cold, tend to fill to capacity by 11. Also, chairs, particularly any in the shade, are usually grabbed in total within an hour after opening. Either go early or late, after 3, when many leave.
Anything special or fun for his age?
for taking the time to post the info. I can only envision a big brewhaha over the Easter egg hunt. It would start with 'Hey my kid........'
Anyway, I may go fight the crowds at BC just to say we did it. Five comes once in a lifetime, and since she'll be scarred for life from missing the Easter Bunny visit her kindergarten year, why not watch her fight for her life among a bunch of little people??? 
