Well, bookings must be very strong this spring because for the first time in many years, WDW is treating Memorial Day weekend as a holiday with extended hours.
The MK will be open three nights until midnight (with later than normal 10 and 11 p.m. closings the week before), which USED to be the traditional closing time for the start of the Florida summer season. Disney-MGM will remain open until 10 p.m. for the 3-day weekend and DAK will see three days of 8 p.m. closings. Sadly, Epcot will not (and likely will never see as long as Brad Rex keeps his job) see any extension in hours).
Overall, this is a great sign for visitors. The past few years saw 10 p.m. MK closings and even an E-Ride Night for Memorial Day itself last year. As someone who spent most Memorial weekends at WDW for the better part of 12 years, it's nice to see tradition returning. Extended hours on a holiday weekend should be a no-brainer.