It is in "soft opening" right now. Meaning that is open but can go down at any time for some problem. My mom was there last week. She was on line for the ride(it was open to all) and about 5 minutes into waiting it shut down(with a ride car at the top with people in it!) it remained closed for the entire time they were at AK that day. So there is a chance that it will be open any day now.
Expedition Everest is OPEN! We were just there for 4 nights and 5 days ... and we had planned going to AK two different days just so we could find it open at least one day ... and it was open both. The first time we all rode we never saw the Yeti ~ we all think the lights were not working right inside the mountain ... because on the other day we went to the park to ride it again ... we all saw the Yeti and we rode at two different times in order to watch our youngest daughter who refused to ride it. It is GREAT. And if you have a child who scares easily and doesn't like to be thrown around on a ride, then don't make them go on it! For the rest of you who like that stuff ... ENJOY !!
Let me clarify the previous post...it is not OFFICIALLY open until April 7. However, as Java said, it is in "Soft opening" phase, which means it will be open much of the time, but not all of the time.
As the last post said it is not officially open but it is shown to be open when you recieve your informatiuon from the hotel and the wait time is posted on the wait list at AK.
Definitely was open when we were there 2 weeks ago. Fast Pass is even up and running! Grab your pass as soonas you get there - we only had a one hour wait time to come back. Hung out in Dinoland to kill time, worked out perfectly. Good luck!