Usually it is an awesome time to go, but you have to remember that this year the kick off for the 50th Anniversary celebration will have just started on the 5th, there are new attractions opening, it will be during the Flower and Garden Festival as well as Star Wars weekends, and Mother's Day falls in that time, as well.
Just plan accordingly. Hopefully, the parks will be open longer and with the addition of the EMH at night, it should be easier for you, if you are staying onsite. Take advantage of those fastpasses.
This is an 18 month celebration, so I would think that the parks will be way more crowded than we have become accustomed to in the past 4 years as more people are comfortable with traveling and everyone LOVES a Disney celebration!