DH here. DW already chimed in on this one, but I have to add my $0.02
DW and I work extremely hard all year and save up our money for our once a year Disney trip. This trip is a culmination of a year's worth of hard work and is very well deserved. This year because of work and school schedules, every day on vacation represents two months of work and taking 3 credit hours of classes for me. In addition to the work vested in my vacation, there is the extra money vested into a fairly expensive trip to WDW. Needless to say, I have a very large interest in getting the most out of my WDW vacation.
As anyone has read the unofficial guide knows, planning is EVERYTHING when it comes to maximizing the value of a WDW vacation. A proper plan can save HOURS a day in trying to accomplish everything that you want to accomplish. In making your plan, the Unofficial Guide points out that at the MK alone, there are 51,090,942,171,709,440,000 different combinations in visiting just 21 rides! When you have 5 days, 4 parks , EMH, crowds, PS and rides to take into account the permutations for planning a WDW vacation are endless.
It is all of this that has led DW and I to spend at least 20 hours of our time planning out our trip in order to make sure we could see all that we want to see in the most efficient way possible. We don't plan our trips down to the second because we know that things can change. But we do plan all of our meals, any special things we want to do and which parks we are going to be at at which time. This plan is by no means excessive as it all fits onto one printed page that we can carry around with us on our trip.
Some may think this is crazy, but people that plan their trips this way can understand the overwhelming sense of satisfaction that comes with knowing that your trip is planned out to the best of your ability.
I think it is wrong of Disney to spring this on anyone going in May less than 30 days before their trip. It's actually even less than that because they have not posted official hours for the evening EMH and have not even communicated when those hours will be available (I spoke to a CM this morning who quoted me the info at the beginning of this thread). While I agree that the actual evening EMH might end up being really cool, this is definitely not the best way to go about testing it.
P.S. I feel sorry for the people that don't have a Saturday scheduled into their trip. Now they have either have to pick between their one chance to see Spectro and an EMH evening at MGM or waste an hour travelling back and forth between the parks.