We went this past Easter (my wife is a Teacher, thus we can only go over the holidays). Anyhow, it was PACKED in all 4 parks. We went President's week the prior year, and it was busy but not nearly as bad. If given a choice, I'd go President's week over Easter in the future.
Fortunately, when we went over Easter we had pretty laid back plans, so it wasn't a huge deal, there wasn't an activity we HAD to do, so if lines were long (and generally they were VERY long) we just did something else. We tried Tour Guide Mike hoping it would help, but were pretty unimpressed for the most part.
Easter's not my 1st choice for time of year at Disney (we also went over Easter about 10 years ago and it was packed then as well), but then again, neither is Christmas, and guess what, we're REALLY pushing our luck by going over Christmas this year LOL. Like Easter, however, we'll be there to enjoy the holiday specific theming/events, and won't worry too much about specific rides or attractions.
The long and short of it with any holiday at Disney is your own mindset. Don't get too worked up on what you HAVE to do, and just enjoy the surroundings and atmosphere. You'll still do plenty when all is said and done!