From what I have read, the following is the 'standard' EMH schedule, that will be followed during the majority of non-holiday weeks:
AM EMH's are Sun-MGM, Tues-DAK, Wed-MK, Thurs-Epcot
PM EMH's are Mon-Epcot, Tues-MGM, Fri-MK, Sat-DAK
Of course this schedule is subject to change, and it is most typically adjusted in order to accommodate holidays and other special events. From what I have seen thus far, it appears that they tend to switch around the AM EMH's far more so than the PM hours.
Lately, the monthly schedules/hours have been going public about 2 months in advance... which can definitely be a pain when one prefers (or 'needs') to make PS's at 90 days out. I'm currently planning our personal park itinerary around the standard EHM schedule, and will adjust as necessary. We are going to have the PH option on our tickets any ways... so even if Disney does adjust the EMH's after I've made our PS's, it shouldn't be all that traumatic for us to work around that.
