We just got back from going to AK for EMH(Morning) and DHS for EMH(Evening) on Monday 9/15/2008.
Of course, you had to show your resort ID to get into the park at AK for resort guests. Was a breeze to get in and bam...on our way to E:E. If you get in for Morning MH - you have to be a resort guest so no need to check at the attractions.
As for the Night time EMH - the park closed at 8 and you could definitly tell that the park had shut down alot of the shops. We rode ToT, RnRC & TSM during EMH (we had dinner as Sci-Fi that went from 8:15 till 9:15 - so we kinda lost an hour of it, but we wanted it that way).
Each attraction we rode, the CM did actually stop us and ask if we had our room keys. I would start to pull them out of my wallet and they would wave us on through. I never saw any of them actually "look" at the key to verify dates or the like.
-------- Off topic for just a bit -------
I will say this - we rode Toy Story around 6:45p - standby (all fast passes were given out by the time we got to the park at 4ish) and the line took us about 75 minutes. The line basically started just past the white wall once you enter the building.
We then rode again about 10:40p - and the line again started about the same place, just as you see all the games inside. This time around - there was no Fast Pass line to compete against. We were constantly moving and were in and out of there in 25 minutes - from the time we walked in the door till we walked out the door.
I really think (as others have said) that this is one attraction that Fast Pass actually hurts. FP riders were still having to wait 20ish or so minutes. It was a totally different line w/FP and w/o FP - in standby anyway.
The Cast Members had the seating down - so it's not CM's holding anything up. The ride was moving right along with no delays at all. It's just FP that really holds this one up.
----back on topic now----
At least at DHS - unless they get a little more detailed when looking at the resort key, anyone with an old one will be able to ride as well.